Plot hole: In this movie Goblin was able to sneak up on Peter. But in the previous movies Peter was able to sense danger from quite a distance away; Green Goblin from a few blocks and the train barricade from over a mile.
Plot hole: Flint Marko has his whole body turned into sand including his belt buckle and any other metal he happens to be wearing. If all of this turned into sand then why was the locket intact without it turning into sand as well?
Plot hole: Eddie Brock couldn't have seen Peter Parker up in the church bell tower from the ground without binoculars as it looked to be 100-200 or so feet above him.
Plot hole: When Harry's pumpkin bomb exploded, disfiguring his face, there were also more pumpkin bombs around him. This explosion should have caused them all to explode, which would have killed Harry.
Suggested correction: It's entirely dependent on how the pumpkin bombs function and how they're built. They're likely built to be able to withstand a certain degree of outside force and heat so they wouldn't just randomly explode during a superhero/villain battle. They also don't seem to function like regular grenades... there seems to be electronic components to them. So it's entirely possible they can't go off until they're activated because certain components inside haven't mixed or been armed. Their rules are just too vaguely defined for this to be a valid mistake.
That's a good point.