I am not associated with the OneCare product, but I use it on several home machines. Two hours is not unusual for any anti-virus product when it's doing a full scan. Just watch how many thousands of files it's scanning. Defrag, too, can take quite some time just because of the nature of the operation (future defrags should go quicker).
I can't address the other issues. However, be advised this this forum is designed for anti-virus on the Exchange platform. Not really the best place to pose this question.
Regards,
Peter Eicher
Forefront Product Manager