Flagging Improvements will Help Moderators' Experiences
I find as a moderator that many users get confused about when they should flag and when they should down vote. I see it go both ways. I see spam that gets down voted (but not flagged). I see questions flagged when a down vote would have been sufficient.
Any improvements to flagging should also include changes to down voting. When somebody down votes, a box could pop up asking for a reason. Clicking on some of those reasons could escalate the down vote to a flag. There could also be an "other" field that would be automatically left as a comment.
Some reasons for flagging could just turn into a down vote. Something like "there are inaccuracies" or "I disagree with this".
I'd also like users to able to flag posts to enter queues. It would be nice to be able to flag questions that need to be edited for grammar, spelling, or formatting. There are plenty of times where you may not be able to do that edit right then, but putting it in a list of things to get taken care of would make the site better.