[2022] Delete members from the server and from config

That is not possible nor supported. You could try to edit the savegame manually if you know what you do, but a lot of things are interdependant and deleting it from the database likely leads to the save corrupting.

Renaming isn't supported either, but you can do so with the /objects edit command by addressing a citizen. Executing the command will usually lead to an immediate crash, in most cases the server boots up fine though with the changed name. Sometimes it works without a crash, then you need to do a restart manually. I won't give any more details though, as that is not supported and dangerous.

We already have discussed that in the past and decided to not do it for solely technical reasons, the suggestion is still on the tracker though, in case that ever changes.