A word to version 3.0:
I planned to do a third version. I've created new perks, and they should work now as well, as can get. Problem is: I cannot make them work as I want without scripting, but scripting is something I cannot do by now. As far as I know, the changes for version 3.0 are possible and others have done such things before, but the problem is: By now I cannot do that due to lack of skill. I need further reading, testing, ... 'n'stuff, you know?
So if version 3.0 will ever come, it most probably won't be a version 3.0 of this mod here, but instead a new mod with extra perks, but don't expect that happening soon. Maybe in some years?

Other plan:
Remove mastery perks from the skill menu and put them inside a MCM menu for best compatibility. Problem: Haven't done any MCM menu mods by now.

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Version history:

v2.2
- 2nd rank of deadly aim now gives 6x damage instead of 15x
- fixed the NoMasteryPerks version

v2.1
- changed only the readme and description

v2.0:
- altered Dark Brotherhood Gloves enchantmentperk, now it affects all kinds of physical weapons (bows, crossbows, all kinds of two- and one-handed weapons)
CAUTION! The in-game description has not changed, but the effect works on all weapons now!
- added sneak-attack-perk for two-handed weapons, now sneak attacks with two-handed weapons will do 6x damage
- bugfix of bleeding damage conditions (I've learned something during the creation of this mod: https://www.nexusmods.com/skyrim/mods/98365/)
- bugfix of critical damage conditions


Description:

This mod adds:
- Weapon Mastery perks, giving bonus damage to your favorite weapontype
- 10 new ranks to Armsman, Barbarian and Overdraw each rank giving additional 5% damage bonus
- 2nd rank to Deadly Aim: sneak attacks with bows and crossbows will do 15x damage
- a sneak-attack-perk for two-handed weapons, now sneak attacks with two-handed weapons will do 6x damage (since v2.0)

This mod alters the following vanilla perks:
- DBBackstab: Now the Gloves of the Dark Brotherhood affect all physical weapons, one-handed, two-handed, bows and crossbows (It also alters the DBBackstabs Magic Effect description) (since v2.0)
CAUTION! The in-game description has not changed, but the effect works on all weapons now!
- Deep Wounds and Bladesman were renamed to 'Critical Strikes' and now affect all kinds of melee weapons (fixed in v2.0)
- Hack and Slash and Limbsplitter were renamed to 'Bleeding Damage' and now affect all kinds of edged weapons (daggers, swords, greatswords, battleaxes, waraxes) (fixed in v2.0)
- the last (5th) rank of the vanilla perks Barbarian, Overdraw and Armsman to make their new ranks accessible
- Deadly Aim to make its new rank accessible

The perk tree structure is untouched.
The newly added Mastery Perks are on the left side from the first perks in the trees.
Skullcrusher and Bonebreaker are untouched, they still only affect blunt weapons.

The new Weapon Mastery Perks are:

Sword Mastery:
1st rank: Your base damage with swords increases by +7, with daggers +3. (Req. 75 Skill)
2nd rank: Your base damage with swords increases by +12, with daggers +6. (Req. 90 Skill)

Waraxe Mastery:
1st rank: Your base damage with waraxes increases by +12. (Req. 75 Skill)
2nd rank: Your base damage with waraxes increases by +20. (Req. 90 Skill)

Mace Mastery:
1st rank: Your base damage with maces increases by +9. (Req. 75 Skill)
2nd rank: Your base damage with maces increases by +15. (Req. 90 Skill)

Greatsword Mastery:
1st rank: Your base damage with greatswords increases by +15. (Req. 75 Skill)
2nd rank: Your base damage with greatswords increases by +30. (Req. 90 Skill)

Battleaxe Mastery:
1st rank: Your base damage with battleaxes increases by +25. (Req. 75 Skill)
2nd rank: Your base damage with battleaxes increases by +45. (Req. 90 Skill)

Warhammer Mastery:
1st rank: Your base damage with warhammers increases by +20. (Req. 75 Skill)
2nd rank: Your base damage with warhammers increases by +35. (Req. 90 Skill)

Bow Mastery:
1st rank: Your base damage with bows and crossbows increases by +20. (Req. 75 Skill)
2nd rank: Your base damage with bows and crossbows increases by +30. (Req. 90 Skill)

Sorry, no separate Bow and Crossbow Mastery, because crossbows have the same keyword as bows ('WeapTypeBow'), meaning it would be necessary to list all crossbows separately in the perk conditions, which would make a patch for every crossbow mod necessary. Only the dwarven crossbows have an additional keyword ('WeapDwarvenCrossbow'), which allows the making of the following perk:

Dwarven Crossbow Mastery:
You handle the dwarven crossbow like no one else. Your base damage with dwarven crossbows increases by +30.
(Stacks with Bow Mastery!)


I recommend to use this together with mods, that increase the difficulty of the game.


added in v2.0: (only in full version!)

Backstab Two-Hander:
Your sneak attacks with two-handed weapons do 6x damage. (Req. 1st rank of Stealth and Sneak Skill 30)



Versions:
- Full version: includes all above listed changes and new perks
- Only Mastery Perks: only the new weapon mastery perks are added, vanilla perks stay untouched (not updated since v1.0)
- No Mastery Perks: only new perkranks for Armsman, Barbarian, Overdraw and Deadly Aim are added, new
mastery perks and edits to the vanilla bleeding and critical hit perks are not included in this version

Note:
You can create a version without any edits of vanilla game content by simply opening the full version in TES5Edit and deleting all lines, that alter any vanilla content (they are marked in various colours). The newly added stuff has white background in TES5Edit. Only the contents of the line "Actor Value Information" must be there, otherwise you POSSIBLY won't be able to take the perks in-game, but I am not sure about this, maybe they would work anyway.


Requirements:
Dawnguard and Dragonborn dlc


Install:
Drop the desired .esp in your data folder of Skyrim and check the mod in your game launcher / mod manager.
Can be installed mid game, no new game necessary.


Update from previous version:
Just replace the .esp in your data-folder with the new .esp. The replaced .esp and the new one must have the same name!
v2.0 only has changes in the full version. The other two versions stayed untouched.


Deinstall:
Remove the respective .esp-file from your data folder.
Usually it's not recommended to uninstall a mod and later load a save, which was created when the mod was installed. I don't know what happens, if you do so. Since this mod does not run scripts or stuff, I guess there would be no problems, but Bethesda has said, that uninstalling mods midgame is not good. When you want to delete a mod mid game, it's better to edit the mod in TES5Edit and simply delete the changes it makes to the game, by clicking on the plus-sign after loading the mod and delete its content by simply deleting each change it makes (left-click on the respective line and press delete on your keyboard).

Incompabilities:
The usual incompabilities with perk mods, that alter the same perktrees as my mod does. Other mods that change the perk tree structures or add new perks into the trees, will be 100% incompatible. A handmade patch would be definitely necessary.
A possible way to increase compability with other mods would be to create a mod, where you can take the new perks inside a MCM menu, but by now I never created a mod with a MCM menu. If someone else wants to do so, do it.


Bugs:
Report them in the comments. On my side it's working as intended.
If I remember correct, I loaded USLEEP when I started creating this mod, so the bugfixes of the edited perks from USLEEP should be included, if there were any bugs in vanilla Skyrim.


Note:
I only tested the full version ingame by myself. So if something is not working as intended, please tell me.
For the creation of the other 2 versions I just deleted the corresponding records in TES5Edit.


Port to SSE:
I don't own Special Edition and was never engaged with porting mods, so if someone else wants to port this mod and reupload it, feel free to do so. Just give me credit by mentioning the original mod.


Credits:
I ran into a problem, when I created this mod. npdogg gave me a hint that lead to the solution.
Here is the thread: https://forums.nexusmods.com/index.php?/topic/7753268-new-damage-perk-seems-to-cause-stacking-problem-wrong-damage-output/