The rear Kappa brake is cable operated just like the C5. Emergency brake is inside of the rotor which does not hcr the holding power as an inner brake but should do. 
Correct; but just like the 5-lug conversion on the CTS-V, when I tried to use '10 Camaro SS rotors, the parking brake drum was too big and I wasn't about to convert the CTS-V parking brake to '10 Camaro SS parking brake.
I guess one target at a time. Front first and see if the rear is as easy.
Bonus point for trying 1g CTS-V Brembo brakes (and its 14" rotors) too

I heard the calipers were cheap.
POS VETT not sure if you have seen older threads, but I have run my stock brakes with ATE DOT 4 fluid and Porterfield street pads at Watkins Glen and other tracks and they held up pretty good. Got a little fade a few times, but overall they held up great.
Going to CarboTech this season and I am hoping to have absolutely no fade at all even at the Glen which has lots of straights.
Lime Rock is in 8 weeks. I'm just doing HPDE not racing, but the stock brakes have been just fine for me with upgraded pads.
I have not read about that. I guess this is more aesthetic than anything. I'm pretty sure the C5 rotors are heavier and is going to take more power to accelerate them.