Turns out the potty was not so bad to get out. It was put in place very much like a home unit with a collar, a wax ring, and a couple studs sticking up that the toilet base bolted to. Once the nuts were off the studs, it lifted right out. Then the collar was held in by 4 screws and it lifted right out leaving a 6 inch hole in the floor.
I'll patch that up prior to putting down the new subfloor.
Once the toilet was gone I picked and peeled at the old flooring a bit to see if it was going to crumble or if there was a chance of getting it out easily.. ('easily' being a relative term, I wasn't expecting it would just pull out with zero effort)
I spent about 25 minutes with my prybar, a wide chisel and a hammer and was able to remove about 20% of the flooring. The area I removed is where most of the curled up edges were and now that its out I'm pretty sure I'm just going to subfloor over whats left. I have some leftover thin green underlayment that goes under pergo type floors from a previous project that I'll use on that side where I removed the vinyl. Its the same thickness as the vinyl I removed so the floor will remain relatively level when I put the new subfloor on top of whats there.
So here are the latest pictures with the toilet gone.. Just a little bit more panel removal up front and I'll be ready to strengthen up the framing.. then the real fun begins.. window removal, rewiring, insulating, repaneling.. eeesh. Little by little, it'll come together :)