Insurance in an amphib is a real chicken and egg situation. No hours means scant chance of getting cover without huge excess and big premiums. You have the hours then and get familiar with the machine, know its limits, keep it in a hangar and begin to wonder about how valuable hull cover will be. Recovery of a seaplane can be dealt with as per the excellent Dale DeRaemer "Seaplane Operations" and its not an impossible task. I know a team who've done a 206 before. Its easy to sleep at night if your airplane is in a hangar, and if something in an operational context makes you uneasy then don't do it. Easy thing to break as I said, and it'll always happen with a crowd looking .....IMHO
As for the paul furnee annual, well he charged us €250 a day plus we covered his expenses, so he's not hard to look after. A week should do an annual on a well bought airplane.
Happy seaplane hunting!