Re: state lettering required?
State registraton has no requirements on name and location. If documented, they require home port on the transom. However, I have seen more than a few that were documented and not lettered.
If the boat is documented it is not required to have state numbers on her, but you do have to pay the taxes and fees for them. If you have to pay, it makes little sense to me not to put them on and keep the local LEO's from stopping you to check your registration....and finding something else in the process.