Not really. He already gained control at the end of The Incredible Hulk.
That was some control he showed aboard the flying aircraft carrier and why Banner is essentially afraid of turning into the Hulk because people might get hurt.
He still had control enough to transform at will. He also won't transform from slight provocations like Tony Stark kept providing (he can probably have sex again now). If something happens to disrupt his control (say that explosion in the helicarrier) then yeah, it's very hard for him to control Hulk. He still fears moments like that, of course, but he generally has a lot more control over Hulk than he did at the beginning of The Incredible Hulk.
Keep in mind there's a big difference between Hulk on the helicarrier and Hulk during the climax of the film. One is essentially Hulk unleashed and the other is a team-up between Banner and Hulk (when Hulk is always at his finest).
Really? They literally had Tony Stark poking and prodding him without getting a reaction and asking "What's your secret?" It took an explosion almost knocking him out completely to shake him and when that happened even Black Widow and everyone on the helicarrier was in danger and he knew it. I felt that was one of the movie's better points which made the "I'm always angry." line make me go "Duh! I feel like an idiot for not figuring this out."
Idunno. I never once thought they were building up to him being in control. Just the answer to how he's been doing it. Dude was pretty zen from the moment Black Widow ran into him in India.
I know he is generally in control when it concerns him turning into the Hulk. I got that point. My point was on how I felt it was muddle as to how much control Banner had when he was the Hulk. Because I felt like the film was telling me that Banner had absolutely no control when he was the Hulk, and then at the end he appears to have at least partial control.
It depends if a smack from the Hulk would kill you.
...who said he was in hiding? He left with Tony
Well I remember Kevin Feige saying on how Stark had only dropped off Banner to wherever he needed to be; and seeing as he's the only real main avenger who doesn't seemingly has anything going for him during the events of Phase 2, it seems odd that this guy would be hiding when he's been accepted somewhat by the public as a force for good.