Drop parachutists quite regularly out of a 500. In UK the aircraft has to be cleared by the CAA for parachute dropping with a flight manual supplement.
The 500 has to have all lose items including seat squabs removed, seat belts must be fitted and used by the jumpers, no more than 4 jumpers, 1 in front 3 in back, obviously doors removed !!!
Must fly not below 60 knts
As for pilot, has to be endorsed by BPA with a bi annual checkride by an approved jump master.
Don't worry about the aircraft c of g as they exit only a split second rocking around ( as you are not allowed to fly below 60 knts - FM supplement ). Most disconcerting is speaking well shouting at someone who is standing on your skids while you are flying at 5 k plus, then the sense of being all alone when they have gone.
Be careful not to autorotate after them, it can be easy to catch them up !!!
Hope this is useful drop me an e mail and I will give you my phone numbers if you want to chat about it