Got a good chunk of time this evening and decided to rip out and replace more guts; in this case, the dependency structure of the goal system. The prototype involved a verbose and redundant system of class factories, and they're simply not carrying their weight. Much better, it seems, will be to implement the dependency structure with the Boost Graph Library, which I'm already using for levels. I had wanted this originally, so now that I'm more familiar with the tools seems a good time.
Naturally, it's a huge mess. I think this will cut out a lot of friction for me, though, with the ongoing plot work. For now, there's a lot of old code commented out, and some half-written graph code awaiting further brain cycles.