Baam is a kid, at most a teenager. Can't just let someone who hasn't even matured run off to do whatever he wants. Jinsung was doing the right thing as he thought that White, a high ranker, was on the train. That guy would not have broken a sweat to wipe Baam off the face of the earth in an instant. Jinsung also manipulated FUG politics to greatly weaken Karaka during the workshop battle. As for being complicit with his kidnapping and trying to mold him into something else, he's acting within his own self-interests for the thing he wants the most. No one will ever treat Baam perfectly. That's exactly why they must control him. He is their best shot, and maybe one day he could screw off without killing Zahard. What will they do then? It's easy for you to say when what you care about is Baam's well-being, but to FUG, he is their only option besides Rachel. Giving a tween whatever he wants without a leash in hopes that he will do what you want is sort of what some would call a foolish plan. It's a real concern among FUG members.