Dylan's self-defence expertise after a couple of lessons was grossly exaggerated in order for him to drop a drunken hobo twice his size & 3 or 4 times his weight, while 3 of that man's friends stood by. That was totally unrealistic (& so doesn't feature in my playthrough). Nobody gets that good, that quick, even a physically fit football (soccer) player. It doesn't matter how proficient a marshal artist Dylan may eventually become, because he's never going to be able to take on a gang with connections & large amounts of muscle. It's not credible.
Some time ago the Dev intimated that the martial arts lessons were not about the Aiden situation.
I disagree about the blackmail set up, while acknowledging it could have been handled better in it's portrayal & it's causes. Schools do very little about bullying, despite what their mission statements commit to. Police do not want to be involved. Seeking to protect her son while "initially" (from Sophia's POV), agreeing to a deal was an immediate solution to imminent danger. Other than sending Dylan to boarding school, or home tutoring, the only solution with any sense of reality would be Carl & his fortune.
What ticks me off is that a satisfactorily nasty end is available for blackmail/Aiden haters but the complaints don't stop. I understand the hate. I loathe the shota with a passion but the Dev is not about to provide a suitable terminal event for it. Anti-blackmail lobbyists are lucky. None of us will ever get ANY game that suits us exactly, unless we can afford to commission one. Aiden is meant to be hated. That's how he's written & people do hate him. That's a sign of a successful character.