When you are parked there, if you are not back by 10p are you locked out?

Yes you are. That is how they keep campers safe

Yes, the gates are locked by the staff at 10pm, if you are not inside you will be locked out and not able to get in.

Yep. Also note that if your vehicle remains in one spot for 72 hours it gets flagged for towing. Friend had that happen once to his car that broke down there as he waited for pay day.

Yes