Mark, we''ve spent the last 6 months ambling from Florida S & E to Trinidad, and I think there are fairly clear answers to each of your questions:
1. Forget CNG as a fuel; just not available.
2. We carry a YB400 and its a good AM receiver, tho'' a far cry from a properly installed SSB with tuner. You''ll also find it''s use incompatible with running the inboard due to rf from the alternator. An external antenna (permanent or a temp one hoisted by a halyard) will make a noticeable difference. But you can pick up a used ham radio (all band transciever, most likely) that has better receiver senstivity, can accept an external tuner (now or later), and will provide better all around service for perhaps no more $$. (Contact the local ham club or one of the big ham stores like Amateur Electronics to begin digging into this). FWIW we cruised with friends who ONLY had a YB400 to rely on (while we were using our ham rig) and they could *usually* get *some* of the WX Nets, but only while the engine was off and reception (propagation) okay. Given the importance of good weather info in this region and the ready availability of it from multiple sources on HF, it''s not an area where I''d try to ''make do''. Your worst possible situation? If you had to accept what the guy in the next boat over told you was what he heard - gadzooks, have I heard some forecasts destroyed by well-intentioned folks after 1 or 2 relays!
3. No island nation or dependency cares a hoot if your boat is insured or not. BUT all the French islands expect your U.S. boat to be documented. For some reason, they don''t know how to deal with a state registration form. No USCG Doc = no clearance. And it would truly be a shame to pass them by!
Let me know if you have other questions...
Jack Tyler
Normally aboard WHOOSH, currently on the hard in Chaguaramas Bay, Trinidad