>>92036124I suppose he'd renovate the beach. There's an awful lot of unused land next to Beach City, given how the Mayor is always pushing for tourism.
I don't remember if they ever had some sort of explanation as to why the corrupted monsters keep acting up, and if there's something that attracts them to the temple.
The gems may be immortal beings with little need to conform to the current society, but as a responsible adult, Steven should probably get them some actual paperwork so they can more easily interact with humans. Licences, ID, etc.
Conveniently, they only seem to fight in areas devoid of human activity. I guess the human population on Earth is pretty concentrated in cities or whatever, and the gem monsters generally avoid them?
Anyway, the Crystal Gems really don't have to care for Steven's upbringing as much, though Pearl would probably still like to do chores like laundry and cooking or whatever.
I'd like to think that he'd remove himself from gem activity, and only assist at their request. He'd get a job, maybe go to school or get a G.E.D. Connie could help with that. Let's say his permanent shapeshifting wasn't a sudden thing but gradually along with Connie, since he's become so close to her.
and then I guess that's that. Pretty much the same as any other adult AU where Steven and Connie share a regular adult life, with the gems as a positive constant in their lives.