As it turns out, trying to shoehorn the Basic Fantasy RPG system into the game was a big mistake. Sadly, it was the kind of mistake that I didn't discover until after I had already tried to do it. So, count it toward the experience gained while creating this project.
I've rolled the project back to the point before I started to change things over (thank goodness I keep backups), and I'm pushing forward with my own home-brew RPG system, which is built specifically for the game and won't have anything in it that it doesn't need. In the end, that was the best move.
In addition, there were some tricky parts to the OGL (Open Gaming License) that I didn't want to deal with. Creating my own system will keep me from dealing with any of that. For my own stable state of mind, I'm glad for that.
Mistakes have been made along the way...more than once, but the project continues. Hopefully I'll reach the point where I can release a demo soon.