Just the way I see it, in this MCU, I don't see Stark or the Illuminati shooting Hulk into space. Someone else would have to do it. Either that, or Hulk/Banner would have to do something pretty egregious or something pretty terrible for Iron Man to decide to do that.....
If they want Iron Man to remain a sympathetic character, many things from the comics would have to change, starting with his approval of the fascist Superhuman Registration Act. If his character doesn't take that turn, then he probably doesn't send Banner to a planet to be tortured, or serve Cap up on a platter for execution.
How do you justify the Hulk returning to earth and basically preparing to murder all the other heroes because he's duped by his insect buddy?.
Hulk to Sue Storm, who is protecting Reed with her force field, and pleading with Hulk to stop:
"If I sent a bomb, killed your husband, your children, your whole world...would you ever stop?!"
Another Hulk quote:
"Don't like it, do you? It's not fair. Not the whole story. You have excuses. Explanations. You're innocent. These people don't know what really happened. They don't know what's in your heart. Now you know how it feels."
Let's face it, the Illuminati were overdue for a good butt kicking.
Not to mention that Ghost Rider, who can see into mens souls, showed up and quickly determined that the Hulk was justified in his actions.
Audiences aren't going to go for that now that they love Hulk and love seeing Hulk team up with other heroes.
There's a lot of truth in this statement, he's a flat out hero now in the Marvel film universe, and kid friendly, so having him go on a rampage and kill other superheroes would be a line they wouldn't cross with his character.