What are the average number of moderator flags on SO per day? I generally feel like I'm flagging way more than the average user, but I'm basing that on the number of spam/offensive flags that come up, which is probably not a good baseline for how many moderator flags come up.
It's hard to say since none of us see all of them. If one moderator clears a flag, it's gone from the queue. I do know that the queue could get to
20-25 100+ flags if none of us logged in for several hours on a weekday.
I wouldn't worry about flagging too much. First, you're limited in the number of flags you can raise in a day. Second, I could probably (but won't) name at least a dozen people who flag more than you do on SO. Third, nobody has complained about you specifically (yet). ;)