I think the Al Bhed thing was to show the corruption of Yevon through Wakka. He hates them because it is what he is taught, as soon as he starts to realise he has been lied to he sees they are good people. Wakka's prejudice comes from being misguided, not because he's a bad person.

The Ronso's do deal with Ronso matters, but that seemed more like a tribal thing than a race thing to me, they all lived on a cold dangerous mountain, they probably would be pretty self contained in their methods.

I thought the Guado bit was just stupid. Having good examples of how racism can occur in good people, and that it's just a lack of understanding was completely messed up by actually introducing an 'evil' race. I know they weren't all bad, but that isn't really what the main plot shows.