I found one more glitch - accidentally, and it frustrated me real strong cause I saved over beforehands T_T I may be forgetting a detail or two.
Basically, if you have a monster with Transform, use it to fight a wild "ditto", and is faster than it, so you transform into it, so it can only copy itself, then switch monsters, so the "ditto" copies it instead, and then switch back and kill the copy (in my case, I had a dragon use Transform, switched to robot, "ditto" became a robot, I recalled the dragon and offed it), your first monster will get the moveset of the second one, and second one would get "ditto"'s moveset and only know Transform now.
Also, if your second monster gets killed, you'll wind up with both it and the first one getting "ditto"'s moveset - this will also happen if you don't fight "ditto", but other monster you transform into, then switch transformer away.
I think it's caused by that thing assigned to "ditto" where it gets the moves of what it was transformed into at the moment you happen to catch it. Guess this game has the same "everyone who uses Transform is Ditto" hangup gen1 Pokemon games have.
Basically, don't Transform and switch monsters, folks.