Global Exclusions

Before I deploy the latest and greatest version of SWV to our enterprise I would like to revaluate our Global Exclusion list.  I have found with a couple of apps when virutalized seem to have problems with the %USERPROFILE%\Local Settings\Temp directory.  It seems like that files would get put both in the base and the write layer than the app would have problems figuring out which one to use.  Adding %USERPROFILE%\Local Settings\Temp as an exclusion on a per package basis fixed but since its happened more than once i plan to add Globally.  Are there any other common directories besides the built in exclusions that anyone else has found helpful to include?  Can file extensions be added globally the same as directories?  Is there any harm in adding common extensions for Office apps (doc, xls, etc)?  Any input you have would be appreciated.