I don't remember Clint and the Hulk really being buddies, but Clint has some cute interaction with She-Hulk in a couple of places. (IIRC, they first meet when one of them rear-ends the other's car, or something minor car-crash-related with lots of shouting. Then Clint comes home and is all "You would not believe the obnoxious woman I met in traffic today! Oh, uh, hi, new Avengers member. Wait, it's you!")

If Teddy was conceived during the first Kree-Skrull war, he ought to be way younger than he is, so I'm going to guess some earlier, unseen thing. That, or timeline screwiness. And speaking of screwy timelines, it's just occurred to me that they could also make Billy and Tommy Wanda and Vision's twins (actual twins rather than reincarnations) from some alternate future timeline and get around the "Wanda has to meet Vision, marry him, have kids, etc. before the show can introduce them." The X-Men got at least three "Scott Summers' future offspring" members that way.