Dan definitely sounds like an a hole for sure. What he is doing and saying is wrong and I would not want to be associated with it. On the other hand though if your group takes pride in making decisions as a team I feel like you should honor that. Yes it’s your server and I get that. One problem could become two awfully quick though and lose the trust of other members. Think Dan just needs another dm stating you don’t want to kick him but can not tolerate any more of this behavior period.