I think the point is that if he stayed with Dallas, he could’ve been sorta exempt from salary caps, but now he is not, and they’re really just guessing how much LA can afford to pay him.
No. There is an NBA rule. If he was with his original team, or he was on a team for four of the seven years, he’s eligible for a Super Max contract, which is 35% of the team’s salary. Because he is on a team for less time, he can only get 30% of the cap. It has nothing to do with the Lakers. If he was traded to any other team it would be the same.