I don't think the problem with Hulk movies is due to Banner's character trying to avoid becoming Hulk. I think the problem is that the movies stories didn't focus on anything but this and who was chasing Banner at the time.
Put Banner in an interesting situation, facing extreme threats alongside other fascinating characters and the conflict between the two personas could fit nicely into this story. Marvel seems to be changing their approach to solo movies and are moving towards films that include one lead and a couple of popular characters so this could work. For example, Dr Strange and Banner/Hulk fighting demons, or with Thor in Ragnarok. A story focusing on Banner/Hulk, but not dominated by the character, would be great.
I agree! I think the stories have to move beyond "the standard chase". They are plenty of other potential stories that could sustain a solo movie & it's sequels. The Winter Soldier is a great model to follow.
Incorporate the supporting characters (Rick Jones, Betty, Doc Sampson, Jennifer Walters, Jim Wilson etc.) to create a bigger universe & storyline(s). Give all the characters something important to do.
Give Banner a high stakes storyline that doesn't involve "curing himself".
There could be some sort of biological threat that Banner need to stop. Banner is a scientist, use this.
Also by using Doc Sampson (or bringing in someone like Hawkeye), you'll get plenty of "human style action". I think this is needed. Hulk can't "fight" people in a traditional sense, but you could still have big solid set pieces (like the Nick Fury car sequence) that don't involve the hulk. Sampson could engage in "the Rock" style action.
For the hulk, he has plenty of villains to face (Wendigo, halflife, the leader, madman, zzazz) But don't just have a smackdown, find interesting ways to use them.
In terms of the hulk, I don't think he should be mindless. There has to be some sort of control, yet some the public still has a huge distrust of him, while others don't. Make it interesting.