It doesn''t sound like you made any mistakes. The timing issue sounds like it is all on his shoulders, as for the questions, if a seller gets upset when you are asking questions, then don''t bother with that vessel. This whole thing sounds fishy, and fishy isn''t good. It smells bad I would walk away.
As for the other boat, do your due diligence, if it seems like a good deal then go for it. What kind of boat is this?