Yes, I'm aware of the Loki thing... but at the same time this is a movie, and as such you usually either go all canon, or trail your own path based on the majority of the material. Changing out members like that, you'd figure they'd go the latter route.
I guess my main problem with our new Bruce Banner is the fact that I feel he'd make a much better Doctor Strange. *shrug* Given a larger cast, and more big name Hollywood actors around him to play off of, I don't think Norton would have been a problem. Thing is, he was recovering the franchise from that Ang Lee horror that came before him... so he was under a lot of pressure to make sure he didn't screw things up. I don't blame him for second guessing Marvel's decisions given those circumstances.
And while I like the characters Hawkeye and Black Widow... there's the problem of losing that drama that came from Ant-Man and Wasp. As I said before, the main crux of this is going to be based on the chemistry between characters... so swapping out major players for different ones leaves a bit of a void. Worse, I fear that Marvel might outright neuter said characters just because it's easier. "Oh, they're trained agents of SHIELD... professionals." I read that as emotionless and dull... but my fingers are crossed that I'm wrong.
Hats, sculptures, and other weirdness... All that is visible must grow beyond itself, and extend into the realm of the invisible. Dumont