This is supposed to be a one day event, yet it will actually be spread over three, which is a bit tedious.
Are people who submit two clues given two votes? I'd limit entries to one each.
How do votes get recorded? Public voting would mean that waiting until last and casting a tactical vote might appear advantageous, unfortunately.
Persoanlly, I'd favour a system of points: everyone nominates their best three clues, giving, say, 5 to the winner, 3 points to 2nd and 1 point to 3rd.
What happens if someone doesn't vote? I'd say their clue should be disqualified as it gives them an unfair advantage.