First of all, this ruleset is amazing. I never went from finding out about a system, to playing the first game, to scheduling a second one, this fast. However, I have some questions regarding the exact way that the "Prime" Special Rule of the Prime Brothers works: Is it correct that a unit with both "Prime" and "Regeneration" (for example an Infiltration Squad with Medical Training) gets to roll for Regeneration twice (against non-spell attacks)? Furthermore, does a 6 on the Hit roll of Rending attack ignore the Regeneration roll granted by the "Prime" Special Rule? And if the unit has "Regeneration" as well, are both rolls ignored?
That's correct, they get to roll Regeneration twice against non-spell attacks (they're pretty damn tough). If you roll a 6 to hit with Rending you do get to ignore both rolls as well, so it's a pretty good counter (aside from spells, which also ignore one of the Regeneration rolls).