As I said, I liked Belgariad/Mallorean. The repetition of Elunium/Tamuli was somewhat annoying, but for the most part, I thought they were still pretty good. What pushed me over the edge was the Polgara novel.
I have to disagree with your assessment of it being an 'epilogue': there was perhaps a bit of that there, but for the most part, it was simply a straight-up retelling of the Belgariad/Mallorean story. It was like a bad TV clip show: there was about 10% new material, but the other 90% was characters saying 'say, do you remember when...' followed by a long summary of the original story, with, sometimes, a few more details of things that Polgara knew (since it was told from her point of view) that weren't in the original story.
It was bad enough that they did that once, but the fact that they had the audacity to do it AGAIN with Belgarath's novel was simply more than I could bear...
Regarding names: if we outlawed every name that's ever appeared in a book, I don't think there'd be anything left (except mine, of course. I spent MONTHS searching for a unique name that had never before been used by anyone. Let me tell you, it wasn't easy, but I did it
) To a large degree, whether we allow a name or not depends on how 'common' the name is, and how prominent it was in the source its known for. Side characters from some novels that are only moderately well-known (as, I'm afraid, the Edding's work is) probably aren't going to be a problem. The name of a Greek god, or something like 'Luke Skywalker' are a lot more likely to be changed.