Do Sea Org members ever get to leave the premise?

The biographies I've read it's not often at all. Not even for a honeymoon. One book I read a mom's daughter was flown to visit with her. The daughter lived at a ranch and rarely saw her mom. The mom didn't meet her at the airport and hardly had time with her daughter. She saw her for meals and stuff if even that. Those in the Sea Org seem very isolated.

As for shopping they have assistants. The biography I mentioned had the assistant at times keeping the daughter company.

I thought Sea Org people are like the "priests" of scientology, meaning they minister to other church members, advise them, etc. That would mean some of them would have to be out in the world for that. Maybe not all, but some at least.