Regarding the user account, as I understand it the installation of Blink at one time created the account IUSER_BLINK for the Blink resource manager to run. Since Blink 3.1, the account ithat is created is called BLINK_<computer name>, so for example I have the account BLINK_DAWACER2 on my laptop. It does need to be there, whichever you have.
Regarding error messages in the logs, I tracked the first start my trouble in the Blink 2.1 update to a complaint about not being able to unregister a dynamic link library, eEyeInthst.dll, because it is in use. As soon as this snag happens, the reversal of the Blink update starts (see partial list below). The update script fails every time. Hopefully, eEye folk can fix this. I am not sure others are getting this same error, but maybe something similar?
September 10, 2007-13:21:23 [02660:04088]--> Script line : unreg "D:\eEye Digital Security\Blink\eEyeInthst.dll" -> Status = Succeeded
September 10, 2007-13:21:23 [02660:04088]--> ExecuteScript: unreg
September 10, 2007-13:21:23 [02660:04088]--> Before calling '"C:\WINDOWS\system32\regsvr32.exe" /s /u "D:\eEye Digital Security\Blink\eEyeInthst.dll"' -> Status = Succeeded
September 10, 2007-13:21:24 [02660:04088]--> Process exit code : 5
September 10, 2007-13:21:24 [02660:04088]--> FileRegistration Error = 5
September 10, 2007-13:21:24 [02660:04088]--> ExecuteScript: Unregistration for D:\eEye Digital Security\Blink\eEyeInthst.dll failed
September 10, 2007-13:21:24 [02660:04088]--> Update Script Execution failed: The process cannot access the file because it is being used by another process.
September 10, 2007-13:21:24 [02660:04088]--> Start Reversal Parsing -> Status = Succeeded