It's not a bad manga I don't get why the hating. He is at the bottom of the food chain, plus he is an orphan with no backers, no one will protect him if he tries to get revenge and the Loli teacher doesn't have power to protect him.
The thing about him lying about his magic is also correct, imagine if were perfect? He is good in academics and good at swordsmanship, if were also good at magic then it would hurt those nobles pride, so as long as he makes them think they are better than him, then they will just verbally abuse him and nothing else. He also has his revenge, he has to do his best and leave this place, instead of hurting some nobles pride and getting swallowed in one of their schemes. ?