The electrical wiring isn't as bad as I'd assumed. The main board is, like, 90 amps plus a smaller 9-amp for the air conditioner rather than the 60 I'd assumed from the house's age. It looks like grounding outlets will be a bit trickier than I'd hoped, but it's happening anyway.
Apparently a great deal of good stuff could happen if I was willing to replace the current roof with a proper sloped one. Wiring, gas lines and so on. That'd cost about $20,000. Not just this second, I'm thinking.