Will wildcards work such as *@*.ru ???
No wildcards aren't yet supported
The only problem of making the group so it can "Manage Users" is that they can easily make someone else an Admin, and that other person WILL have access to everything since they can manage the groups they are in, so I say there should be a way Mods could ban IP's without going into the Admin CP, I made a suggestion about it here:
http://mods.mybboard.com/forum/showthread.php?tid=869