OT: I don't know if I could cope with a 7 second cooldown on charge but I suppose it'll actually be less than that because of the mod weight glitch. And I disagree with Clyde, Incapacitate can only affect 1 enemy at a time and the enemy has to be down to health already, so it's not terribly useful.
How long does Carnage prime for a fire explosion? I'm guessing it's not long enough to self detonate on this setup.
It's around six seconds with the glitch, give or take, plenty good enough on a krogan with cyclonics.
I personally agree with you that incapacitate doesn't work very well on the krogan kits, because anything that can be knocked down with it is headbutt fodder anyway, but I can see it being useful on the BF3. I might respec him to use 5a eventually.
Carnage's prime is really short, probably around 1-2 seconds I'd say from experience. No FE's for this build unfortunately. 