As for there fertilizer? I think it's a matter of not knowing how to use it IMO.. I must say, I've never killed a plant, or seen bad results.
Problem is.. people don't realize that with miracle grow they already have over the top strong doses so with peppers you want to cut them in half, atleast, everytime.
Peppers, especially hot ones, will respond horribly to a heavy dose of fertilizer. So as long as you cut it, You'll be okay. I know it's not the best fert out there for a long shot, but its affordable compared to most, it works, you just have to know what to use it on and at how much strength. I mean come on.. if their ferts were really sh**.. Do you think you'd see them stacked on every nursery, super market, garden center, and hardware stores shelves? There's a reason for that
Brandon