Yea, a small buff to cutlasses speed would do it good.
Also, I have argued in previous threads that the current >cap reproduce penalty for Z viral shreddders is a bit too harsh currently.
For the energy thing, in my game, I am actually quite greatful for my ZPG. Granted, I am using lots of mini-forts, starships, and trader goodies. If you are using a more conservative build, then yea, I can see that energy would be overpowered. So yea, I guess the current energy system is OP, as you really only start worrying about it once you get to near max cap on dang near everything (except for single HW non-coop, before you take any planets, you will start hittin energy limitations before then). It seems like the energy pressure should start happening before that, even with several planets captured.