The WCM log say that you have a healthy WSUS box to start with. The DoSync error can be from a bad SUP install, hotfix missing, update not installed, IIS error. If you have a heathy wsus and WSUS says it is working but can't sync then check IIS and make sure it is healthy as well.
http://www.sccm-tools.com http://sms-hints-tricks.blogspot.com