On grammatical class:

re'e
emotion category/modifier: religious/spiritual/worship - sacrilege.
ro'a
emotion category/modifier: social - antisocial.
ro'e
emotion category/modifier: mental - mindless.
ro'i
emotion category/modifier: emotional - denying emotion.
ro'o
emotion category/modifier: physical - denying physical.
ro'u
emotion category/modifier: sexual - sexual abstinence.