rom editor...

where i can find a rom editor for FF4?

There is none, to my knowledge.

Of course, you could use a hex editor, which would require knowledge of what everything does on a byte level, so would be extremely difficult to do for most people :p

The only rom editor I have found in the past years is this one (ftp://ftp.wolfmahheaven.net/FF4Edit.zip). It only let you edit the 3 overworld maps.

I had come across a DOS based editor for it years ago. I'll try and see if it's still on my old computer. Now, if ya wanna change stat values, look on sites like gamefaqs.com or rpgclassics.com for hex editing tutorials for this game.