All good questions. Remember you will be paying property tax every year on the boat so if you can choose a jurisdiction with the lowest property tax that would be ideal. I think you would need to establish residency in that state to do so perhaps by having using a mail forwarding service
there - but that is my impression and if anyone knows for sure please correct me.
One thing you may or may not be aware of that stung us was the "Use tax" that Washington
state applies on boats that are brought here from outside the state. If you are in WA waters for appx. 60 days or more you will have to pay them a one-off 10% tax on the value of the boat based on the bill of sale
- unless you can prove you paid sales tax elsewhere at the time of purchase
Otherwise this is a great place to work on the boat plus it sits on the edge of the world's best cruising grounds.