Just when you will add those anti-crit perks and Crit Modifiers, please think about BG Bazooka sniper, that can become unkillable/unstoppable (high range, high damage, hard to blind, hard to cripple, high hp (-10 crit tables = way less dmg for snipers, + additional lvl's = even more hp, while BG sniper will still only need like 2 shots to kill everyone w/o any crit perks or whatever)
You could just make KD be lower chance, and make perks that will split snipers into 2 builds.. crippler or crit hitter, so you can be crippler but do way less dmg than crit hitter, with lowered chance of arms crippling, or crit hitter = way less chance to cripple, but higher dmg.
So you would need to decide if you want to be crippler, have more chance to cripple but less crit dmg (BG will live longer and have a chance to do dmg/kill before he cripples you)
or crit hitter, way less chance to cripple but you do more dmg when you crit, so if you are lucky, you will kill bg faster then he will kill you. BG's will have more chance he won't get crippled arm so he can fire at you more, and kill you faster than sniper, because sniper could be unlucky.
You could make new perks for BG so he can decide if he wants to get less KD or less Arm/Body Cripples, just remember to not remove them totally. So like 2/4 new perks so BG can decide that he takes this one, and will get like 20% less chance of crippled arms/body parts, but it reduces his DR or whatever so he will get more dmg from crit hits (eg. +2% to opponents Crit Table)
Or he can take 2nd perk = less crit chance/crit dmg, but higher cripple chance.
You really have to think about this because otherwise you will make a way for unstoppable/unkillable BG tanks (high HP, best armors = almost no crits dmg, cripples, + anti-crit perks)
I also think that there should be more useful perks on 3rd lvl, because now it's only like 70% awarness and 30% thoughness, there should be something as good as awarness so people won't see info about player but will get something different which is as good as awarness. This would make fighting more based on real skill of choosing opponents etc. 'coz not everyone would run with Awarness, and wouln't know about armor or weapon or hp.