Since rooting only modifies internal system files, you can move stuff between sdcards at will! But that's also true whether rooted or not. You can always copy your data onto another card and use the new one. The only caveat is to try and always make a FULL copy. Several apps will use your external card to store app data. They will continue to work without the card, but you may lose preferences, settings, etc.
Oh HEY, that was your first post!!! I forgot to say welcome to the forum!!!