If a song was imported into iTunes in AAC format if you make an AIFF version of the song would it be the same quality of a song that was imported as an AIFF file?

Not the same! A song in a commercial CD usually/ normally was stored in an AIFF format. If you imported/ converted this song into an AAC format, then there will be some quality lost. And, if you then export/ convert this song (from AAC format into AIFF), that lost part is never be regained; the later AIFF song is not the same with the first(original) one.