As for the question of whether to remove the AC components, ask yourself why did you get a
carbon fiber hardtop?
OK, maybe it was given to you free, so you didn't have to buy the fiberglass version
.
But the short answer of course is of course less weight is better. Will you notice any effect of taking out 20-30 lbs? Likely not. So is it wasted effort? I'd say no. Colin Chapman had it right.
I also think a 5% gain from lowering is overstating things a bit. But lowering is a tactic automakers commonly use on "eco" versions of cars (Chevy Cruze the latest example). Results will vary from vehicle to vehicle.