Katrina's reaction to darkmoon being willing to actually pay for something is both hilarious and completely appropriate XD

Just because Darkmoon's willing to discuss payment doesn't mean he's actually going to do it. He might be willing to entertain the idea on principle, but just is pretty much never satisfied with how things aren't horribly in his favor.

Darth Cariss is right, as this has been witnessed before, although I don't think it was in any of the main storyline stuff. Also, Captain Sprockett seems to be female, and the only other female currently around isn't interested in having sex with anyone around, maybe Darkmoon is just getting a jump on Angel trying to jump her? Now, as for the different conversion types, maybe certain ones are only compatible with certain ship types (due to how the ships were built), also there have been a few different variations of airships in Final Fantasy, including blimp-like ones, and maybe that's where some of the 'earlier' versions came from as it took awhile before someone got the helicopter style to work.

I'm pretty sure that the previous six were; Sloop Sloop-of-War Ketch Caraveille Brigantine and the Schooner

Very possible as well. Also, don't forget that he covered all of the cannon ports on that galleon, she doesn't have any offensive abilities anymore and is strictly a transport ship.