Or maybe Peter, or any of the superheroes in the Marvel Universe who are supposed to have a BRAIN, could come up with ANOTHER way of defeating Norman Osborn, rather than simply accepting that the ONLY options are either "kill Norman Osborn" or "sit by impotently and do nothing."

The ONLY reason Norman hasn't been defeated already is because the writers say so. What's the point of telling a story in which none of the characters move forward in any significant way, and nothing of value is accomplished? If the writers WANTED to, Peter could FIND A WAY to defeat Norman, or at least MARGINALLY put a dent in his armor, but they chose to turn him into a PUNCHING BAG for an entire arc, whose only valuable contribution was to give Harry advice that will probably wind up destroying Harry in the long run.