Ghost was a product that Symantec purchased many years ago, but the team that developed it was laid off a few years ago. What remains of support is based out of India, so your expectation that Symantec support should know their product is sadly incorrect. Of course in an ideal world, documentation should be accurate and complete, but after 35 years in the IT industry, that has yet to happen.
A former Ghost developer, Nigel Bree, occasionally posts in these forums and he is probably the best person to give you chapter and verse on the internal workings of Ghost. His postings are well worth searching for if you want to get to know the product better.
Regarding the service account, this is an internal account in the operating system which runs processes at an elevated level - superior to the Admin account in many cases. It is the account used by many of the services that run in the operating system, and is also the account used by the Ghost client. Unfortunately, there is no single answer to these errors, as any problem with the Service account could cause the issues you are experiencing.
I can't think of any quick way to diagnose the problem, so what I would suggest is a strategy that removes as many variables as possible. The first thing I would try would be to create a WinPE bootable USB stick or hard disk, and run Ghost manually from the WinPE command line, and restore your image to the test hardware manually, from a local USB device. Then check that it starts up OK. If it does, then it points the finger at a networking problem. I hope you can see my strategy here - try things one step at a time to narrow down the actual point of failure.
Incidentally, if you are using multicast over your network, you need to have IGMP snooping enabled as otherwise the process will hang at some point.