as someone with manager rights I believe I can answer your questions.

if you are a manager, your clan page looks like this:

then if you go into "invite a player to join then you can invite anyone on your friends list (if you have blacklisted them you can't invite them). You can also revoke/re-send invites, which is why DARKLORDS can send so many, even if you ignore them.

P.S. they just go down there list inviting everybody they can find :)

now we know who has rights in the clan...