Please explain your feature request to the best of your abilities:

Add an admin command for Event War that allows you to remove a town or nation from a specified war manually. If possible also, this would also remove all their contributions (if any) such as points so it's as if they were never in the war.

That's fine, if participants are removed at the start of the war they would have scored no/negligible points anyway.

I don't think I can account for scored points, since points do not track who scores them. Removing a town/nation/resident should be fairly simple though.