Thanks for the input. I might put this on the back burner for when I'm bored and need a medium sized project to fill some time. I'm really wondering how well a 1/2" or so kerf will keep a saw straight. I guess I could run some experiments to find out. I know a deep kerf does a wonderful job, but kerfing planes don't go all that deep, so that's part of my hesitation. That, and what I'm doing now works, assuming I put in the effort and focus. So it wouldn't open up new doors for me, but at best make things a bit easier.

And I always flatten at least one side of a board before resawing, if not both sides, and joint an edge. I never thought to use a straight edge to mark a resaw cut before. But, David's post does introduce me to the idea of getting around that, should the need arise. It might be a good idea with some boards that have a little wind or warp to them, so I have maximum material to work with after the resawing lets some of those internal stresses out.