ADV! RPG

I thought about that. Then I realized that we know a lot more about the mid-to-late game than the beginning. Plenty of the early towns/caves and such weren't labeled, or weren't placed on a map. If I start at the end, I can see where stuff is for sure, then see if I can have the party double back to that town. As far as the storyline switches go, I've been able to just add them in as I need them (so far). I'm actually not going straight backwards. I'm jumping back a plot point, then filling it in forwards. Jump back, fill forwards. It's working pretty well, so far.
About the multiple parties: Yeah, I know I could set that up pretty easily. Right now though, I really don't feel like doing it. And I haven't really thought of how to switch the people mid-battle, although I could figure it out. Basically, I'm focusing on the map and plot together, then the smaller plot details, then the items and weapons, and finally the enemies.