It's not rocket fuel itself, it's an oxidizer. Storing it in aluminum bins as PEPCON did strikes me as quite risky, since aluminum powder with such an oxidizer would make a good solid rocket fuel or explosive. As a kid, friends and I used to make our own fireworks with ammonium nitrate fertilizer. These days if you buy much of that and aren't a farmer you'll likely get a visit from serious men in dark suits.

Yes, and TATP is a high explosive. MEKP is almost as powerful (5200m/s detonation velocity vs 5300m/s for TATP) but much more useful commercially. It's a precursor for all sorts of plastics.