Okay. Got it resolved.
First, I removed the Restart Required value in the key: HKLM\Software\Microsoft\Windows\CurrentVersion\Windows Update\Auto Update. This resolved the constant need to reboot.
The CBS errors were tied to unknown files attached to KB3020369. I ran pkgmgr again which did not create any prompted errors but I could still see the update was installed. I removed the mum and cat files from servicing\packages and then cleared registry data for it. All in all, there were 34 entries. Upon rebooting, I reinstalled the update that I had sourced from the Update catalog and it went through normally. On reboot, CBS log shows the install completing successfully without error. I am running CheckSUR again before I start installing all other updates.