I'll handle this as two different posts, a complaint against mike's behavior and the suggestion per se.
Staff's duty makes it so that being allowed to speak with anyone at anytime, even more to those that don't want to listen, is a must. Verbal warnings or requests to change something in your base because it's hurting the server are some examples of those situations, and allowing /ignore would lead to arguments caused by the lack of communication. If you were to really need to /ignore a staff member it would mean that, the said staff member, is doing something wrong and that may be breaking one of the rules. In that case, a complaint will be better than simply ignoring them.
About the complaint, since the screenshots were taken outside of a CL area (forums, discord or servers) and outside of mike's staffing duty they will be taken for what they are worth. Since he's the leader of that clan he's free to disband it, and you are free to make a new one and invite whoever you liked from that old clan, if he were to delete that new clan however, that'd be a different story. And the rest are just bits from a conversation without the context around them. Mike will be given a verbal warning about his behavior and hostility.
If what he's telling you in-game is bad enough to deserve an /ignore, take some screenshots and make a complaint, since it's probably breaking a server rule.