I wish I could help out with the new tempcraft, but every time I log in, I fall through the map and into empty space because my connection is too slow and the map has yet to finish loading. If my internet was faster, I would play and help out. I used to be able to come onto classic all the time.
Download Spout, if for no reason other than the fact it loads the world THEN logs you into it (as opposed to the norm, throw you into the world and then load it). A crappy connection still wont really enjoy playing MC...but you might be able to wander around worlds with Spout.
EDIT: and btw, only 1 plugin was even needed to fix the entire mess.
Logblocks.
Find the intruders names...rollback to infinity, 0 damage to map, in under a minute.