McAfee Security Suit on only 1 or 2 PC's on home multi-PC network

Have a five PC Home Network running Cox Premiere Internet Service.  My questions are:

1)  Is Cox McAfee Security Suit running well for most Phoenix users...and

2)  Do all home PC's need to run McAfee...I have a 5 PC home network....or can say 3 run another (Norton, AVG, etc) and only 2 run Cox McAfee Security Suit....

Thanks,  TiminAz