While just having a quick surf of the net...I came across this on hans-zimmer.com. It's Hans being Hans and he's always a good interview. Here are a couple of quotes:
"You're a composer second and a film maker first."
"My job is to do the things they (directors) can't imagine."
"At it's best it enhances everybody elses contributions. At its worst, it probably ruins your movie...I try not to ruin to many of them."