Re: Nicknames for Faolán?
You could always pull the nickname from the sound of the second syllable, something like Lenny, Lonny, or Lon. Faolán is so compact, I really don't think it needs a nickname.
You didn't ask, but Faolán is awfully close to "failing" in my accent (also the #1 suggestion made by my spellchecker), and I have a hard time appreciating it.