Now included in  LEGO - Loot Economy Gear Overhaul.

This mod is divided in 2 parts that do 2 separate things:

- The first part/main mod "No Randomly Added Gear Bonus Stats" is a script-only mod that removes weapons&armor's bonus stats that were added at random, as opposed to the bonus stats that are a part of that item's definition.

In the vanilla game most magic and master-quality gear items have not only the bonus stats/abilities they were predefined with but also get a random amount of extra bonus stats/abilities that are picked at random from a large generic list of bonus stats/abilities and added on top of that item's native bonus stats. 

Example: an elven steel sword is predefined as having a +10% critical hit chance bonus stat, the game then will still randomly add one or two extra stats/abilities to it such as +igni sign intensity or +bleed or + armor piercing  or +poison etc(see pic), those stats being picked at random from a list of over a dozen possible stats, and chosen differently every time you pick up such a sword.

This mod makes it so gear items only get the bonus stats/abilities they were predefined with.

The mod shouldn't permanently remove bonus stats from your save: if you uninstall the mod, drop an item and pick it back up(or whenever a new item is added to the player) the game should once again add random bonus stats to it. 

 - The optional mod "Maxed Out Gear Stat Values" is an xml/bundled file mod that is just just my own version of Gotcha44's excellent No Random Item Stats mod. It further removes randomization from your gear by additionally making it so the actual values of weapon/armor stats are also fixed instead of randomized between predefined minimum and maximum values (values always maxed out now). 

Optional mod "DLCArmorSeparateNGvsNGP" makes sure that merchants in NewGame don't sell the NewGamePlus version of DLC armor sets and that NewGamePlus merchants don't sell the NewGame version of those same armor sets. In vanilla they sell both versions depending on your level, possibly leading you to acquire multiple versions of the same dlc relic armor set in a single playthrough, making it so the relics you buy aren't necessarily the best possible version of those items etc.


Install:
Manual download (recommended): just extract the \modxxx folders into your The Witcher 3 - Wild Hunt \Mods folder (where your other mods are, in your game install folder). Run Script Merger  to merge the files if you have other mods (that means MERGE ANY CONFLICTING BUNDLED XML if you're using the optional mods).

Vortex (not recommended): automatic. (Vortex not recommended for TW3mods).


Uninstall:
 Unmerge the files if you merged them before.

Changed files (main mod):
\content\scripts\game\gameplay\components\InventoryComponent.ws
\content\scripts\game\player\playerWitcher.ws

Changed files(optional mod):
\dlc\
dlc1_shop.xml
dlc5_shop.xml
dlc14_shop.xml

\gameplay\items\
def_item_armor.xml
def_item_armor_relics.xml
def_item_boots.xml
def_item_crafting_armor.xml
def_item_gloves.xml
def_item_pants.xml
def_item_quality.xml
def_item_weapons.xml
def_item_weapons_crossbow.xml
def_item_weapons_relic.xml
def_item_weapons_relic_autogen.xml
def_item_weapons_secondary.xml

and same files in \gameplay\items_plus\