for HS some things I might consider; a buff or bandana which could replace the mask, clear cheap safety glasses or low tint sunglasses for eye protection for mostly high wind, map of the city in case you unexpectedly end up somewhere unknown (like a kegger or feedtrip gone wrong). finger nail clippers could replace a small cutter or try a swiss key that is rarely ever noticed on a key ring. a swiss fire starter might be allowed.

The +1 for being in HS is that while at school during an emergancy, you're priority #1.

Make a separate kit for after school.