It's tough to edit a poll and retain its validity. What would prevent someone from changing the answers once a poll started? Even adding additional answer choices once a poll starts invalidates it. Got a typo? Fix it before posting it.
Best idea is to think it thru before posting it. There's no rush. Thinking it thru first never fails, if you've actually thought it thru first.
But in any event...
Yeah, we used to be able to ask multiple questions. That's sorely missed. I don't think multiple polls is the answer in that regard. And a preview would be nice, too.
