Because the votes are cast in turn order, each player will know the votes of players who voted beforehand.

None of the candidate permanents are targeted. Players may vote for a permanent with protection from white, for example.

Players can't do anything after they finishing voting but before the "winning" permanent or permanents are exiled.

In the unusual case that no permanents have any votes, nothing is exiled.

No player votes until the spell or ability resolves. Any responses to that spell or ability must be made without knowing the outcome of the vote.

Each player must vote for one of the candidate permanents. They can't abstain.