Magnets, yes. in the Emporium shop on international street. 2-3 bucks. although i havwe only seen ride picture/logo magnets
.
Fireworks: yes, and they are pretty good! they occur every night, at park closing, on all nights when the park closes at 10PM or later.
Average coaster waits, I'd say 30 minutes or less, for best lines, go to River town first, ride Beast and Tomb Raider, then go through the park counte-clockwise.
no-miss? The Beast, Flight of Fear.