The sensible default position for all those things would be to keep them exactly the same as they are now.
We're currently, as a fully paid-up member, compliant with all the necessary regulations and rules. We're not going to suddenly stop being compliant with all those rules one second after leaving. After we've left and we want to change things we will need to renegotiate things that are affected as a result of the changes we wish to make - that doesn't mean renegotiating everything all at the same time.
Of course, I don't expect the EU will accept this sensible default. It's the inability of the EU to accomplish anything in a sensible manner and timescale that is one of the main reasons why a member country would want to leave in the first place.
We're currently, as a fully paid-up member, compliant with all the necessary regulations and rules. We're not going to suddenly stop being compliant with all those rules one second after leaving. After we've left and we want to change things we will need to renegotiate things that are affected as a result of the changes we wish to make - that doesn't mean renegotiating everything all at the same time.
Of course, I don't expect the EU will accept this sensible default. It's the inability of the EU to accomplish anything in a sensible manner and timescale that is one of the main reasons why a member country would want to leave in the first place.