1. Throw some alcohol on it, push around to see if you feel any teeth and then move on.
2. Never had anyone constrict me except Caesar when i was trying to unhook his upper lip from his tooth. I just let him constrict my leg and he quit after a few mins.
3. Only have Dozer the gila. I use a glove on him but he does like to climb off the glove and up my arm and sit on the inside my elbow just relaxing.
4. Bad idea imo no matter what the species. If one gets sick, everyone can be screwed.