1) SNES9X also has an SPC-ripping function, although it takes more time (File -> Save Other -> Save SPC Data). Testing music in ZSNES is a very bad idea anyway.
2) If you're porting from a SNES game, it helps a LOT to have this SPC player
, which allows you to listen to a single channel at a time.
3) I can't think of anything that MarioStarLuigi didn't already say.