Pretty much this.

I remember nine years ago when this site had a blue design ban bets were enforced. Then it became too much of a burden for thr mod team to arbitrate unclear bets. So probably not, but if you feel you can handle it.

No, but I usually get banned when I engage in them :)

The problem is unclear bets, which never should have been made in the first place.
If there is such an unclear bet, throw it out and don't spend time on it, because it wasn't valid to begin with.
That was the original propisition in poll, that clear bets could be enforced.
If it's unclear, it isn't valid. People can realize that at the time the bet is made.

Oh yes, absolutely. Ban bets are cool and more people should be doing them, is a great way to back your words with something more than just words, which in a place plenty of nonsense predictions based on pure emotions can be helpful for everyone. I think mods should enforce them and make sure the loser gets banned.

If both parties agree that mods can be involved, I see no problem. I don't see the point of ban bets in the first place though.