I think part of the problem is that media has trained us to think of super geniuses as either absent minded autists or smarmy jackasses. The idea that a normal seeming guy could have an IQ of 170 becomes difficult to find believable.
As for the anger part, I remember for a long time in the comics, it wasn't just anger that triggered the Hulk transformation. I remember an issue of Defenders where Bruce was afraid to go to go with his teammates to the movies for fear that something would trigger a strong emotional response- not just anger, but fear, anxiety, frustration, what have you.
In Hulk vs. Wolverine, Logan triggered the transformation by stabbing a drugged Bruce and leaving him to bleed out- the terror of dying apparently being the catalyst.
That having been said, no, Mark's performance isn't that of an angry man. But Bruce Banner doesn't have to be. He's just someone who repressed a lot of his emotions due to trauma and abuse with another guy living in his head who doesn't know the meaning of the word "repress".