you have experience, you have/will have sufficient funds, you seem to know what you are doing and you are young. On this board this is very refreshing, but why the flock are you asking these questions.
GO, GO, GO.
Forget medical insurance, you can get private medical treatment for a fraction of the US cost down island and in most countries it is very acceptable. If the boat is your major financial asset run the numbers and then decide on insurance. I would prefer to spend the money refitting.
I'm trying not to sound like a hard ass but... I'll bet that some folks who walked from US Airways flight 1549 are rethinking their life plans as we speak.
For the record I cruised for two years in the Caribbean, I'm back refitting a new boat and then I'm off again for good AND I'm old and don't know anything.