I voted for the simplest option but have some comments:
1. Abstentions, for whatever reason, should not count towards the final count. So why have them? If everyone knows the context of an invitation poll - ie either have your say now or forever hold your tongue - then the reasons for abstention (not acquainted, unsure, can't be bothered) are irrelevant.
2. Ethel suggested that each person should have a veto option - if so, then I think just one veto per user per year.
If there is a veto option consideration must then be given to whether the black-balled person can be voted on again - it would somewhat sabotage the veto in that case.
I seem to be repeating myself everywhere I go; first I won't talk, then you can't shut me up.
But I'm also very confused with all the threads up right now and the conversation spread amongst them all.