Q1) Is there a specific file extension(s) in SharePoint should be execluded from McAfee scan (if YES What these file extensions )
Q2) What is the credential preveileges suppose to use when you work with McAfee Security for SharePoint in case if not allowed to use the FARM ADMIN FOR SHAREPOINT
Q3) What is the important reports require to generate in front of customer
Q4) How to integrate with ePO
Q1. No there aren't any specific extension you should exclude from on-access scanning
Q2. you really should use a farm admin account. if you can't then see the product guide for msms 3.0. it has a section about setting up a user with least privleges.
Q3. in epo there are specific reports that can be run for msms. any one of the reports are important depending on what it is you scanning for and want to report on.
Q4. there is a management extension and report extension that need to be installed into epo for msms 3.0. additional information about this is included in the product guide.