My 2 ideas (probably often suggested elsewhere):
1. Server should auto-enable polls at round start and disable them after x seconds round time (x 30-60 i would think)
This would keep polls to the beginning of battle, so they aren't that disturbing and the chance that people actually look at it before pressing 1 or 2 is higher. Therefor the results should be less random.
2. Add the possibility to add a reason to the poll which will be sent by the server.
Right now i mostly see dead people starting polls (e.g. because they just got tk'ed) and so only other dead guys can see the reason (if they give any). If the reason was sent via server message/something like that everyone could see the reason and again that should make results less random. Although a "dead to living message channel" for everyone might be abused.