Asshole? He has a bit of a caustic humour, but that's more low-key. Ghost has a more oberserving personality and he when he gets a liking to you, he will protect you. As a vigilant Ghost has a sense of justice, a bit twisted thanks to his paranoia, and so did help the Secret Warriors and Avengers that time against Osborn.
Many of his Thunderbolt's teammates owe Ghost their lifes Headsmaster, Paladin, Moonstone, etc and does see his Teamates like Juggernaut as friends. It's just, if you are a psycho like Mr.X or Crossbones, Ghost is going to plan a way to kill you in a "accident".