UPDATE 2014-02-17:
Disclaimer:
This project has been deprecated; as a consequence it should not be installed! If you choose to do so, no support will be given by the author.
I have added the the source code for previously unreleased version: 0.80. The files are uncompiled and untested! They should be used only for educational purposes. If you really want to give it a go and install, you must know how to compile the source. Instructions on how to do this can be found on various existing educational resources (a.k.a use google)! The files are password protected to make sure this notification has been read.
Password: lovebird

Acclaimer: I give my consent for the source files to be used in any fashion, the users sees fit. This includes uncredited use of the source, reuploads of the source and/or binary and modification of the source and binary. This project is a 100% "open source".

Known bugs/quirks:
-- Spells unequipped from player wont update until you leave the menu. This is because you cannot remove/add a spell to force an menu update, unlike items. Still working on figuring out how to force update while magic window is open.

What is it?
Simply put, Restricted Skyrim is a mod which adds level and skill restriction to all Armors and Weapons in the game. Yes, even Weapons and Armors that come from other mods!

How does it work?
If you don't meet a requirement for a given item it will be stripped from you when you try to equip it. You will be prompted with the requirement you failed to meet. There is an MCM Menu where you can change the requirements to suit. If you choose to change the modifier value, you will be stripped of all items currently equipped.

Is this really necessary?
Nope, but since I did the work, I might as well share it. To be honest it's not really the kind of mod I would use but I needed a hobby project that was purely scripting based. I'm not good at 3D modeling, voice acting, sound designing or level designing and I hate using the Creation Kit (keeps crashing). Add to that, my limited imagination and this is the kind of mod you get :)

Features:
Pre-Released Phase:
alpha 0.1 - Level restriction to all items based on value.
alpha 0.2 - Changed level restriction for keywords; Imperial, Iron, Hide, Draugr, Studded, IronBanded, Steel, Leather, Dwarven, Elven, Scaled, SteelPlate, ElvenGuilded, Orcish, Glass, Ebony, Dragonplate, Daedric, Dragonscale, Dragonbone -- TODO: Silver, Nightingale, Shrouded + Immersive Armors keywords.
alpha 0.3 - MCM Menu added, skill requirements added (not as strict as level requirements -- needs balancing).
Testing Phase:
beta 0.4 - General testing and bug fixing.
beta 0.5 - Restrictions on spells.
beta 0.6 - Better balance overall.
(TODO):
beta 0.7 - Better restriction handling for uncategorized weapons and armors.
beta 0.8 - Better UI management (the messagebox popup will do for now).
beta 0.9 - Diversified controls and settings via MCM.
release candidate 1.0 - Code clean-up + add some support for popular mods (not critical, as it should work well with all mods).

Installation:
Download the loose files - Unzip - Copy the loose files to your Skyrim/Data folder
OR
Use the Nexus Mod Manager to download and install

Requires:
SKSE - http://skse.silverlock.org/
SkyUI - I'm not supporting vanilla UI atm (although it will probably work fine)
Dawngaurd - I'm not supporting non-Dawngaurd atm

Compatible with:
Any mod that doesn't dynamically change the name of items.
Any mods that don't try to restrict what the player can equip.

Recommeded mods:
Apocalypse Spell Package by Enai Siaion - http://skyrim.nexusmods.com/mods/16225
T3nd0s Skyrim Redone - http://skyrim.nexusmods.com/mods/9286
Immersive Weapons by Hothtrooper44 and Ironman5000 - http://skyrim.nexusmods.com/mods/27644
Immersive Armors by hothtrooper44 - http://skyrim.nexusmods.com/mods/19733

Categorized Weapons and Armors:
Level ~~2; Skill ~~15 = ImperialLight, ImperialStudded, ImperialHeavy, WeapMaterialImperial, WeapMaterialIron.
Level ~~6; Skill ~~20 = ArmorMaterialHide, ArmorMaterialIron, WeapMaterialDraugr.
Level ~~10; Skill ~~25 = ArmorMaterialStudded, ArmorMaterialIronBanded, WeapMaterialSteel.
Level ~~12; Skill ~~40 = ArmorMaterialLeather, ArmorMaterialSteel, WeapMaterialDwarven.
Level ~~17; Skill ~~45 = ArmorMaterialElven, ArmorMaterialDwarven.
Level ~~22; Skill ~~50 = ArmorMaterialScaled, ArmorMaterialSteelPlate, WeapMaterialElven.
Level ~~30; Skill ~~55 = ArmorMaterialElvenGilded, ArmorMaterialOrcish, WeapMaterialOrcish.
Level ~~38; Skill ~~60 = ArmorMaterialGlass, ArmorMaterialEbony, WeapMaterialGlass, WeapMaterialEbony.
Level ~~43; Skill ~~65 = ArmorMaterialDragonplate, WeapMaterialDaedric.
Level ~~46; Skill ~~65 = ArmorMaterialDragonscale.
Level ~~48; Skill ~~70 = ArmorMaterialDaedric, WeapMaterialDragonbone.
-- Daggers and Staves have a universal offset of '+10 to Skill Requirement' and '-10 to Level Requirement'.
-- Lighter armor parts have a slight offset to Level Requirement.

Uncategorized Weapons and Armors:
bValue: --BaseGoldValue; no enchantments or upgrades have any effect on level requirements,
unless its clothes, which has too low BaseGoldValue by default.
-- Clothing basevalue is 'enchantmentvalue/2+basevalue'.
level: --The level requirement a Armor or Weapon with a give BaseGoldValue will have.
bValue= 1; level= 1
bValue= 11; level= 1
bValue= 21; level= 2
bValue= 31; level= 3
bValue= 41; level= 4
bValue= 51; level= 5
bValue= 61; level= 6
bValue= 71; level= 7
bValue= 81; level= 8
bValue= 91; level= 9
bValue= 101; level= 10
bValue= 111; level= 11
bValue= 121; level= 11
bValue= 131; level= 12
bValue= 141; level= 12
bValue= 151; level= 13
bValue= 161; level= 13
bValue= 171; level= 14
bValue= 181; level= 14
bValue= 191; level= 15
bValue= 201; level= 15
bValue= 211; level= 15
bValue= 221; level= 16
bValue= 231; level= 16
bValue= 241; level= 16
bValue= 251; level= 17
bValue= 261; level= 17
bValue= 271; level= 17
bValue= 281; level= 18
bValue= 291; level= 18
bValue= 301; level= 18
bValue= 311; level= 19
bValue= 321; level= 19
bValue= 331; level= 19
bValue= 341; level= 20
bValue= 351; level= 20
bValue= 361; level= 20
bValue= 371; level= 21
bValue= 381; level= 21
bValue= 391; level= 21
bValue= 401; level= 22
bValue= 411; level= 22
bValue= 421; level= 22
bValue= 431; level= 23
bValue= 441; level= 23
bValue= 451; level= 23
bValue= 461; level= 24
bValue= 471; level= 24
bValue= 481; level= 24
bValue= 491; level= 24
bValue= 501; level= 25
bValue= 511; level= 25
bValue= 521; level= 25
bValue= 531; level= 25
bValue= 541; level= 26
bValue= 551; level= 26
bValue= 561; level= 26
bValue= 571; level= 26
bValue= 581; level= 26
bValue= 591; level= 26
bValue= 601; level= 27
bValue= 611; level= 27
bValue= 621; level= 27
bValue= 631; level= 27
bValue= 641; level= 27
bValue= 651; level= 27
bValue= 661; level= 27
bValue= 671; level= 27
bValue= 681; level= 27
bValue= 691; level= 27
bValue= 701; level= 28
bValue= 711; level= 28
bValue= 721; level= 28
bValue= 731; level= 28
bValue= 741; level= 28
bValue= 751; level= 28
bValue= 761; level= 28
bValue= 771; level= 28
bValue= 781; level= 28
bValue= 791; level= 28
bValue= 801; level= 29
bValue= 811; level= 29
bValue= 821; level= 29
bValue= 831; level= 29
bValue= 841; level= 29
bValue= 851; level= 29
bValue= 861; level= 29
bValue= 871; level= 29
bValue= 881; level= 29
bValue= 891; level= 29
bValue= 901; level= 30
bValue= 911; level= 30
bValue= 921; level= 30
bValue= 931; level= 30
bValue= 941; level= 30
bValue= 951; level= 30
bValue= 961; level= 30
bValue= 971; level= 30
bValue= 981; level= 30
bValue= 991; level= 30
bValue= 1001; level= 31
bValue= 1011; level= 31
bValue= 1021; level= 31
bValue= 1031; level= 31
bValue= 1041; level= 31
bValue= 1051; level= 31
bValue= 1061; level= 31
bValue= 1071; level= 31
bValue= 1081; level= 31
bValue= 1091; level= 31
bValue= 1101; level= 32
bValue= 1111; level= 32
bValue= 1121; level= 32
bValue= 1131; level= 32
bValue= 1141; level= 32
bValue= 1151; level= 32
bValue= 1161; level= 32
bValue= 1171; level= 32
bValue= 1181; level= 32
bValue= 1191; level= 32
bValue= 1201; level= 33
bValue= 1211; level= 33
bValue= 1221; level= 33
bValue= 1231; level= 33
bValue= 1241; level= 33
bValue= 1251; level= 33
bValue= 1261; level= 33
bValue= 1271; level= 33
bValue= 1281; level= 33
bValue= 1291; level= 33
bValue= 1301; level= 34
bValue= 1311; level= 34
bValue= 1321; level= 34
bValue= 1331; level= 34
bValue= 1341; level= 34
bValue= 1351; level= 34
bValue= 1361; level= 34
bValue= 1371; level= 34
bValue= 1381; level= 34
bValue= 1391; level= 34
bValue= 1401; level= 35
bValue= 1411; level= 35
bValue= 1421; level= 35
bValue= 1431; level= 35
bValue= 1441; level= 35
bValue= 1451; level= 35
bValue= 1461; level= 35
bValue= 1471; level= 35
bValue= 1481; level= 35
bValue= 1491; level= 35
bValue= 1501; level= 36
bValue= 1511; level= 36
bValue= 1521; level= 36
bValue= 1531; level= 36
bValue= 1541; level= 36
bValue= 1551; level= 36
bValue= 1561; level= 36
bValue= 1571; level= 36
bValue= 1581; level= 36
bValue= 1591; level= 36
bValue= 1601; level= 37
bValue= 1611; level= 37
bValue= 1621; level= 37
bValue= 1631; level= 37
bValue= 1641; level= 37
bValue= 1651; level= 37
bValue= 1661; level= 37
bValue= 1671; level= 37
bValue= 1681; level= 37
bValue= 1691; level= 37
bValue= 1701; level= 38
bValue= 1711; level= 38
bValue= 1721; level= 38
bValue= 1731; level= 38
bValue= 1741; level= 38
bValue= 1751; level= 38
bValue= 1761; level= 38
bValue= 1771; level= 38
bValue= 1781; level= 38
bValue= 1791; level= 38
bValue= 1801; level= 39
bValue= 1811; level= 39
bValue= 1821; level= 39
bValue= 1831; level= 39
bValue= 1841; level= 39
bValue= 1851; level= 39
bValue= 1861; level= 39
bValue= 1871; level= 39
bValue= 1881; level= 39
bValue= 1891; level= 39
bValue= 1901; level= 40
bValue= 1911; level= 40
bValue= 1921; level= 40
bValue= 1931; level= 40
bValue= 1941; level= 40
bValue= 1951; level= 40
bValue= 1961; level= 40
bValue= 1971; level= 40
bValue= 1981; level= 40
bValue= 1991; level= 40
bValue= 2001; level= 41
bValue= 2011; level= 41
bValue= 2021; level= 41
bValue= 2031; level= 41
bValue= 2041; level= 41
bValue= 2051; level= 41
bValue= 2061; level= 41
bValue= 2071; level= 41
bValue= 2081; level= 41
bValue= 2091; level= 41
bValue= 2101; level= 42
bValue= 2111; level= 42
bValue= 2121; level= 42
bValue= 2131; level= 42
bValue= 2141; level= 42
bValue= 2151; level= 42
bValue= 2161; level= 42
bValue= 2171; level= 42
bValue= 2181; level= 42
bValue= 2191; level= 42
bValue= 2201; level= 43
bValue= 2211; level= 43
bValue= 2221; level= 43
bValue= 2231; level= 43
bValue= 2241; level= 43
bValue= 2251; level= 43
bValue= 2261; level= 43
bValue= 2271; level= 43
bValue= 2281; level= 43
bValue= 2291; level= 43
bValue= 2301; level= 44
bValue= 2311; level= 44
bValue= 2321; level= 44
bValue= 2331; level= 44
bValue= 2341; level= 44
bValue= 2351; level= 44
bValue= 2361; level= 44
bValue= 2371; level= 44
bValue= 2381; level= 44
bValue= 2391; level= 44
bValue= 2401; level= 45
bValue= 2411; level= 45
bValue= 2421; level= 45
bValue= 2431; level= 45
bValue= 2441; level= 45
bValue= 2451; level= 45
bValue= 2461; level= 45
bValue= 2471; level= 45
bValue= 2481; level= 45
bValue= 2491; level= 45
bValue= 2501; level= 46
bValue= 2511; level= 46
bValue= 2521; level= 46
bValue= 2531; level= 46
bValue= 2541; level= 46
bValue= 2551; level= 46
bValue= 2561; level= 46
bValue= 2571; level= 46
bValue= 2581; level= 46
bValue= 2591; level= 46
bValue= 2601; level= 47
bValue= 2611; level= 47
bValue= 2621; level= 47
bValue= 2631; level= 47
bValue= 2641; level= 47
bValue= 2651; level= 47
bValue= 2661; level= 47
bValue= 2671; level= 47
bValue= 2681; level= 47
bValue= 2691; level= 47
bValue= 2701; level= 48
bValue= 2711; level= 48
bValue= 2721; level= 48
bValue= 2731; level= 48
bValue= 2741; level= 48
bValue= 2751; level= 48
bValue= 2761; level= 48
bValue= 2771; level= 48
bValue= 2781; level= 48
bValue= 2791; level= 48
bValue= 2801; level= 49
bValue= 2811; level= 49
bValue= 2821; level= 49
bValue= 2831; level= 49
bValue= 2841; level= 49
bValue= 2851; level= 49
bValue= 2861; level= 49
bValue= 2871; level= 49
bValue= 2881; level= 49
bValue= 2891; level= 49
bValue > 2901; level= 50