Needles alone are enough to one shot everything in game, just need right gear.
Plus stormstrike is ok at lvl 1 since you won't really use them, 2 needles have low CD plus wolf fang fist... Trust me on that.
Opening Roar is must if you want KD, since when you stun them you want fast to charge up and with roar maxed you charge RP ball in few sec.
Plus when you buff yourself, let them touch you a bit and you have RP ball ready aka KD.
Figters were speed based and critic based.
If you go only for one, you won't be good enough for anything.
Speed, Critic power and KD's are good, plus I think you want this long range KD for Dojo wars too and PVE.
Might - it gives you same stats everytime.
S.Roar - gives you stats based on default/original stats you have and more you upgrade weapons, higher it will give.
Simple put, S.Roar will pull more power than might, every time and since you will use thunder, you want that auto attack power high plus high critics when you make them.