Does this tractor beam, or any other planned tractor beams, have enough power to stop an active ship from escaping its pull? Like if you get a lock on it and then they power up and try to take off.

All things being equal, probably not. But for instance, if this came and tractor beamed a Dragonfly or an X1 or a Nox, that's going to be significantly harder for that to get away. And likewise, if we had a super uber capital ship with tractor beam technology and it tried to do it to a smaller ship, it makes it much harder to do. But on an equal footing, it's not an instant win, but it requires effort from both sides to succeed.