Im very often at the Buckmoth Legion Fort and its crashing soOo many items. Its happening if I enter/leave the fort through the door. Often I have to restart the game 6-8 times until Im able to leave/enter the fort. If its crashing I just get the message that Oblivion is not working - Close program/Debug.
Im not sure how to figure out the problem. Does anybody else got these problems with the Buckmoth Legion Fort too?

#1
I'm going to start the quest line of the Imperial legion soon, i'll report back if I encounter the same issue.
But I had this issue too at Vivec, exiting to a outdoor area. But it's not as worse as you discribed; as in ratio. Seems hella anoying.