You're right about zero tolerance, but I think it needs to be done by the NFL. Otherwise the bad boy that has talent will merely go from the team that canned him to one that is full of bad boys.
I really like your idea about the team suing the player for losses to the organization and finding and training someone to fill their slot. I would go one step further and write it into their contract that if they misbehave in a way that gets them canned, their contract is now null and void, i.e. the team will not be buying out their contract. This would need to be, again, an NFL stipulation (if you want to play football in the NFL, you have to have this clause. no exceptions) maybe done as part of the union negotiations when it's time to renegotiate the collective bargaining agreement.
I miss Tom Landry. He would not have tolerated any of this crap from any of his players. They would have been gone, no matter how good they were.
This is a GREAT idea!! Excellent.