What stats exactly are you wanting? It's possible to do calculations based off database data and displaying it as a field using incubator project CB Query Field which outputs the results of a database query as a normal field seen on users profile.

The "Content Author" plugin found in Plugin Management will allow display of users articles within their profiles. It only shows date, title, hits, and ratings however. Commenting is typically done from 3rd party extension as Joomla doesn't have official commenting support so the tab won't display comment count without editing it. The incubator project CB Articles can also be used to display articles on profile with display count drop-down, paging, and searching features.