His app is good, and I see where you seem to be going with him in a lot of ways. However I have, as usual (lol) a couple questions.
First and foremost, if he's a werewolf, how is he managing at school? He might have been living with a pack before school (and perhaps at breaks) but there are a couple of problematic things that need to be dealt with. First, he would be required to use wolfsbane while he's in school. In PA, werewolves have no selective abilities to control their lycanthropy. They become brutal and animalistic. The only way of managing is through the use of wolfsbane. Is he doing that, or what are you doing with him during the full moon? The school would consider him little more than a killing machine, I think, when he was transformed, otherwise, and would surely not allow him to remain in the castle or on the grounds around other students.
Second, the fact that his mother disowned him would be, in effect, a legal matter. Someone has to have legal custody of him and would be responsible for signing things like school break forms, passes to Hogsmeade, blah, blah....Is Mom still doing that? Or does he have someone else that has stepped up to be a legal guardian? I am sure wizarding law, like most laws, would either require that he have a legal guardian or the Ministry would be appointed as his guardian if there were no one else. That might affect your personal plotting for him.
Further, the Ministry has tracers, according to canon, on underage magic, and it is illegal for him to be using magic off school grounds as a minor--even in a werewolf pack. How is he managing to do this? While I'm sure most wizarding children have at least dabbled in magic prior to Hogwarts, a kid like Toby who is, for all purposes, orphaned, would surely have nabbed the Ministry's attention somehow for all sorts of reasons if his history is accurate.
I like the premise. I am not opposed to the disowned child theme. I am merely saying I'd like to see some of his backstory polished a bit. Let me know if you need some help with it!