My headcannon is that MacCready actually has a soft spot for non-feral ghouls. I know a lot of fans have interpreted it completely the opposite based on his back story with Lucy. I’m basing this off of a couple of in-game interactions with non-feral ghouls - his attitude and trust with Daisy, his interaction with Hancock when you switch companions, and the fact that he hates it if you kill Trish during the drug deal.
As for his relationship with Hancock - I think they’re pretty good buds, and Hancock has probably hired Mac the Merc for odd jobs. I imagine they’re a pretty effect team in a…. wrecking havoc kind of way.