A report on the pepper plants: Before just pulling them, I tried the foliar spray that Kyle had mentioned. Dissolved a couple antacid tablets in a pint jar of water and then sprayed it on about a week ago. Plants are looking way better - not much brown spots or yellow leaves and new growth. Unfortunately it's probably too late in the season for a few of them to produce any peppers, but the spray definitely helped the pepper plants. Going to have to keep mental note of that.
Today we gave the tomato plants a cut back - cut off the tops (especially since they were getting too tall and were starting to fall over) and trimmed the sides a little. Can actually see some of the tomatoes growing now and, for what I've read, the plant should now focus more on maturing the fruit that is there instead of new growth.
Harvested more peppers today - getting a good harvest of them every few days.
Something has been eating the brussel sprout leaves. NOT happy. Still some surviving. Need to figure out what it could be.