The current energy system just isn't balanced at all! Here are my suggestions, make everyone have 15 energy points (if not, at least make a energy limit in customs, it gives a lot of energy advantage with perks specifically because you can have so multiple good perks with this amount of energy!!).
I want vampire to at least be allowed for all level 1 players if the energy system will not change
here are some suggested weapon energy balances
-vampire perk stays the same energy
-ammo perk goes down to 7
-healing shield perk goes down to 3 (or 5 if it is buffed)
-insight perk goes down to 2
-all other weapons or perks stay the same
-(if extra 30% damage perk is added back, it will be 5 energy, however there should be a change with this perk! Only bullets are affected by this perk and all those bullets will have the visible glow like the nukes have!)