Maybe I am going about this all the wrong way, maybe this needs to be a fighter subclass: Invisible Blade.
Inchoroi, if you have access to it, look at the Invisible Blade prestige class for 3.5 D&D, its in Complete Warrior page 45. That is the inspiration for all of this along with trying to make daggers a weapon worth using in combat.
Yeah, I dug it out about an hour ago. Took half an hour just to find the book...haven't looked at them in years.
I don't think the Bleeding wound thing is going to be viable, not because it'd be broken (it wouldn't) but because it might be easily forgettable. I'd probably allow it (or, alternatively, add it to the Assassin archetype for rogue) but make sure that the player keeps track of it, so I don't have to. I also think it kind of violates the spirit of 5e, since things like that are supposed to be giving advantage/disadvantage, rather than static bonuses. However, if I were to do something like that, I'd do it like this:
Dagger Master version 2:
Dagger Master
Prerequisite: 13 Dex
You are a master of small blades and knowing where to strike to do the most damage.
* Whenever you successfully damage an opponent with your daggers, you may inflict a wound on the target. You may only inflict one wound per round, but may inflict wounds on multiple opponents in an encounter. Whenever you make a successful attack, you deal one additional slashing damage per wound the target possesses. Targets can remove wounds with a successful Medicine check, at a DC equal to 8 + your Dexterity modifier + your proficiency bonus; healing class features or spells automatically removes all wounds on a target, as well.
* If you successfully parry a melee attack, you can expend your reaction, and gain advantage on your next attack against that target, before the end of your next turn.
