HG, p11-12 gives no power requirement for reaction drives, so the rockets need no external power.
A good call. Okay, so you keep cruising along at whatever you were doing with the reaction drive anyways.
To be absolutely literal - not sure if zero power means not affected. Sorry the book isn't on me at the moment. But 0 power can still be affected, what's t exact language? 0 is negligible power (example I think a fixed missile rack I also 0). But as it stands now, can a craft reduced to 0 power (or less?) assign 0 power to systems? Lol