"I don't know if any casinos still pay shills for poker"

I doubt that there are any shills still on payrolls in NV. If there are, they can not hurt you in a poker game. Gaming regs say a shill can not call a bet. All they can do is ante or post blinds, then throw their hands away as soon as a bet is made.
Prop players are used in most local's oriented poker rooms. It is a tough job!!!!!!