no, it doesn't run slowly on the ps1 because your disk is scratched; the PS1 port always has long load times.

I honestly can't stand playing it on the playstation because of the long, long, long wait to open the menu and start a battle; just play it on the snes or your computer. It'll run very smoothly. If there are any unlockable features on the ps1, they probably aren't worth it anyway.