Highlight the word, then hit the Swype key. It will confirm that you want to delete it.
Edit: I think I'm wrong... It seems like it only works with words you add to the dictionary. I tried deleting "IM" and it wouldn't let me.
None.
With Gorilla Glass, I don't feel like having one is necessary. Plus I haven't found a screen protector that doesn't give it the "rainbow effect".