This is just my opinion. Firstly, there is no evidence that Foxy is a good guy, or that Mangle, or anyone for that matter, did the bite. Foxy makes the same sound as all the others when he attacks in all three games, debunking the "Malfunctioning voice box". Foxy is also the same as all the others in all three games: an animatronic animal possessed by the vengeful spirit of a brutally murdered child. Even more so in the second and third games. In 2, he's, like the other original animatronics, neglected,torn apart, and he attacks you a lot more viciously. There is no proof of him being "hacked" ingame. Stop making things up. There is also no evidence of him being "threatened" or "checking on you" ingame. Again, making things up.
Given that Foxy is an animatronic, I don't think he necessarily has a morality of any sort. Whether or not the animatronics are possessed and not merely malfunctioning is up to speculation, but I believe it to be the latter because according to the first game, the animatronics attack you because they believe you to be a wire frame, and they're programmed to place wire frames into suits that have sharp wiring inside them. I don't think he's a villain as much as he is a robot that's at the fault of a programming error. Is he good, per se? ...No, but since Foxy isn't a living thing, and therefore isn't able to make conscious decisions, he can't really be classified as a villain.