Re SHC: I guess I'm an old softie, but I don't like the idea of permanently expelling anyone.
Years ago, I sat on the review committee of an organization whose board had expelled a member. I voted to uphold the expulsion (it involved misuse of organization funds and involving the group in a lawsuit); nonetheless, when I noticed there was no provision for re-admitting an expelled member, I got a bylaw passed allowing for such, subject to a 2/3 vote of the board.
Note: To date, no expelled member has ever been readmitted, and yes, we did get our money back.