Great suggestion on the opt-in advertising! I created a new section for that :)

The geography/location/language is to some extent covered by the "optional personal profile data".

"Metrics" like what you are requesting have already been declined by the dev team, due to the decentralized nature of the blockchain. Since users view post data through many platforms, and the blockchain itself does not record views - the number of views through Steemit.com would be a misleading/incorrect number.

Regarding "Groups", I suggest you create a post on this with what your thoughts are, and get some feedback from the community. If it seems like something a lot of people are on board with, then send me a link to the post and I'll review.