I now have WSUS merged with our SCCM environment by using a couple articles.  

Now my question is that most of the articles when they were creating search criteria most are limiting the search to just "MS" Bulletins.  Is there a reason for this?

I know previously when we released updates we released all updates for say windows 7.  Is there a common practice for search criteria for windows 7 machines?

Using the "MS*" for filtering is to simply get only the monthly security updates. If you want all the updates for Windows 7, simply remove that additional criteria and only use the product as search criteria.