what sort of posting frequency does a user need to hit to get the 'My Badges' stars highlited?
Not aiming to up my postings but am just curious.
If you are referring to this:
Those stars are different -- they are associated with the rating of the individual piece of content (i.e. forum post/reply, blog article, wiki article, file/image, etc.) That is one of a number of factors that then gets factored into each members "badge score", but is not the only thing that contributes to the level you have achieved.