Re: One profile page to rule them all
Without direct edits to the the profile template it’s very hard to extend it, if not impossible. I’ve managed to add post count to the profile without template hacks via my post-count-plus plugin but putting in an avatar or gravatar is impossible without a hack.
But it’s easy to add tabs to the profile section via plugins.
You can make supplemental pages.
Just make a new tab to list all WordPress posts/comments.