Sullivan - as a ln, it's fine. As a fn, it could so easily shorten to Sully, which is not particularly flattering.
Frederick - family name for me, though not close to the top of my list. Good name; I might actually like the name better if I didn't remember my uncle
Fred so clearly!
Abel - family name on DH's side. Pronounced AHbel, long a sound. Not a name that I could readily warm up to; too much 'innocent victim' built in.