In my version on the AU, Keith is still half-Galra, and Shiro's "brother". They grew up in the same little farming town, and were actually pretty close. Shiro's "grandparents" were had some experience with raising an alien kind, given their son literally came out of crashed spaceship, and were a help when Krolia left Earth (for some reason, cause in the AU, Alteans and the Galra exist, but they are all refugees not really at war with the each other. Haven't really thought to much into that). Shiro and Keith were very much play mates, mostly because Shiro could really take Keith's rough housing. Keith couldn't take the full force of Shiro's, but it was more than a normal human. So in a way, Keith is kind of like a Jimmy Olsen sort of character, as he is a good friend to Shiro and knows who he is.
Hunk, I haven't thought about too much. I think I want him to be human and just 100% a normal guy. But I am sort of like the idea of him running like an underground alien cafe/bar. Like he is kind of the guy you go to get help and shelter from (or ids or to fix alien tech cause he'll figure it out). He's place is somewhere both Keith and Shiro like to go (and later Lance). Though I am also very partial to the idea of Hunk just being a normal guy that is just Shiro's neighbor (that maybe Keith has a little crush on) and Lance befriends him one day. And Hunk is just sort of like "okay Shiro has a weird friend but whatever" until he finds out Lance and Shiro (and Keith) are aliens. He still their friend and everything but it explains a lot, but he just DID NOT EXPECT that. But Cyborg!Hunk does sort of work, because Cyborg and Starfire were pretty good BFFs
