This is some of "ideas", since PB 2.5 isn't 100% complete yet.
Civil Security Ghost
The invisible is good...But to he's a ghost right? Can he like....Possess thing? Here my idea... Civil Security Ghost has ability to possess dead body.. But they can't possess body that already in half pieces or destroyed.. As long that corpse has its body (that mean they possess even the corpse has no head,legs and etc)
Some character ability
Civil Security Heavy can tank many damage so that his ability.. Maybe they can add Civil Security Boss some guns profession? Proxy can booster herself to move,swim and shoot faster..Android will likely take reduced damage from guns..and agile...You'll get it...
Disarm
If you shoot the hands, it will likely have chance to disarm him ..
Zombies
This will be likely a big-thing if they created it... Zombie are really effective in close-combat. And extremely agile and fast.. They will become more faster if they lost their body...Zombie also has chance to disarm player.
Armor change
This will be likely only available in SP... Players can change their body (armor) from a dead corpse..
That all (Sorry for ma bad enlisghh)