Desdichado
Hero
I saw a lot of obvious sword & planet influence in the solar system of Golarion, so that certainly seems like a fun idea if it goes along those lines somewhat. A bit more Burroughs and Brackett and C. L. Moore rather than Barrier Peaks would be much more up my alley.When I think "outer space" it's going to probably feel a lot more like the stuff we're doing in Planet Stories. Very pulpy, pretty gritty. Expedition to the Barrier Peaks type stuff. Not so much Spelljammer.
Also: the swashbuckler is an archetype that's sorely lacking in the base class line-ups, and a rogue/fighter is a poor substitute for one. I think that's a much more glaring hole in the line-up of classes than an oracle or a cavalier (who can be credibly done as a paladin or as a fighter with a lot of mounted combat feats.)