Hi everyone!
I’ve checked out another topic where this issue was discussed, but it seems there is no solution yet, right?
Maybe I’m missing something and there is a way to exclude staff from the statistics (topics created, posts created, etc.)?
Also, it seems Replies section includes not only replies themselves, but all the actions on the whole (‘made this topic public’, ‘assigned this topic’, hidden replies, etc.) - is there an option to track replies only?
You can use the data explorer plugin to generate such statistics, though I don’t see any built-in queries that do that.
Mostly, if your community is new enough that staff actions are a sizable amount of your total traffic, then you can count the number of user posts by hand. 
@pfaffman thank you for your suggestion!
Yes, I do count it manually now but as you guess it’s far from being convenient It looks like a real basic feature, and it’s sad it’s not available yet.
Thank you anyways for looking into this!