at first glance it sounds like a good idea, but...
First of all I don't think polls are a good indicator of the general attitude of the community, since a lot of people wouldn't vote in them, most of all probably those that don't write in the forums
Silence is generally considered as consent, so as long as people don't voice their disagreement it's safe to assume they like changes that are made to the game, and many of the users don't take this game very seriously either so they don't find the need to write in the forums.
And, if polls could be added to new forum topics then every new thread in suggestions would have a poll, every thread in help would have a poll (Should I play a) Motion b) run and gun c) push the ball.... or should I train this player as center, pf or sf and so on)...
Nothing personal, but in my opinion polls wouldn't be of much help
suggestions like yours are of much greater help to the community, no matter if they are accepted or rejected