Thanks for the link for that thread PixalZA, I've been searching through threads like crazy, but that one looks like it has some good info. I had some success yesterday with projecting a curve and using "split mesh with projected curve" and then rebuilding the area around the hole.

One trick I found for spliting faces is selecting two vertices and holding down shift + rmb to get a marking menu that has "connect components", rather than the interactive split tool. It's nice and quick and less finicky.