You're using some of the most notorious examples of silly match-ups that don't make sense, particularly the Firelord one. In each and every case, when two characters fight, the victor is determined not by raw power or cunning, but by the writer's (and in the worst cases, reader vote) needs for a particular story.
I think Spidey SHOULD win most of his fights; he's plenty powerful, and one of the most experienced heroes in the Marvel Universe. But I find the suggestion that Norman Osborn isn't in his "league" a little strange. He's the most notorious villain in a rather sizable rogues gallery. That makes him the very definition of the same league. No one has done more to make Peter Parker's life miserable, and when the Green Goblin does win his skirmishes, they tend to result in iconic things like the death of Gwen Stacey.
Norman Osborn with tech upgrades should be considered a scary thing.