Agreed; if you know an exclusion isn't needed for your environment you are welcome to remove it.
Note though, once you veer off from the default rule set, each rule you modify becomes "Your" rule and McAfee has limited ability to change it.
i.e. Your changes get written to the registry which overlay and take precendent to our default rule content file (vscan.bof). So if we update the content file, your changes still overrule ours.
Also note, you may think that reducing the rule content by removing unnecessary process names etc is shrinking the overall memory footprint needed to track the rules - but it is not.
I like the idea for attaching policy XMLs to the KB. You should submit this to our PER database.