"You're starting to believe, but I don't think you're quite there yet."

You're right. The proof (for me) will be how this forum's methodology holds up in *my* pool, right? But everyone here has convinced me that I don't have to blindly and ignorantly follow a local pool store's advice on how to care for my pool (for which I heartily thank you!). Moreover, you've raised an interesting, viable alternative that I'm willing to try -- keep up my CYA level, keep up my FC level, watch over my CC level, and shock only when the pool needs to be shocked. Doesn't have to be once a week. Doesn't have to be once a month, even. Just when I need it.

So, I'll give it a go. My "insurance policy" against algae, though, is that I'll still add a maintenance dose of polyquat each week. The relatively low cost of doing that gives me peace-of-mind. What I need to work out now is how much time the SWCG needs to operate to keep up the FC level. Over this week and next, I should be able to nail that answer down.