Does Dana White make any money out of this at all if the fight is boxing? I mean did he made a single cent from Conor vs Mayweather fight?

If he didn't get any money at all and just hoped that Conor fighting Mayweather would get more attention to UFC than it doesn't worth it at all. UFC is already quite known thing and there are really EA sports games based on it (and boxing is not quite popular anymore in gaming) and you are still trying to get exposure for your organization by letting your fighters do whatever you want? I don't think so.

If Khabib goes and fights with Mayweather in a boxing match than I seriously believe Dana should give him a punishment like get the UFC some percentage of the winnings or something. If you sign a contract with some place and than just go do other work there should be consequences.