If it's all from his POV, then how do you explain the constant shifts to other people's POV - the Joker, Vicki, etc.? Anyway, one of the central tenets of Batman - ANY Batman - is that he acts completely different as Wayne, to throw people off the scent. My guess is that the whole 'channeling his rage and anguish' thing is taken much more literally than usual here, so that we essentially have two people in one body - a suave, sophisticated, close-shaven lady's man, and a raging brute with stubble rough enough to use as sandpaper. (Seriously, did you notice that he can be perfectly groomed as Bruce, and then, in the very next scene, IMMEDIATELY grow a five o' clock shadow as Batman? It's freaky.)