That is entirely up to them. Not a legal issue.

While you call this a "wrongful eviction" it isn't. IMO it is nothing.

Please see other answers to your duplicate question.

The judge will not read anything that is not filed in court and sent to the other side.

It is if you say so. IMO adults should not date children, but that is your call.

Not clear to me at all, but perhaps there are additional facts.

It appears that the school did not believe your son. At the hearing you will have the opportunity to convince them otherwise.

Generally speaking your employer can fire you for any, or no, reason.

I am not sure where people got the belief that schools had to get "permission" to speak to children but they don't.

IMO there is nothing about what they did that warrant the expense of a lawsuit. They were completely within their rights.