I would not be able to say. I don’t have access to Blizzard’s QA infrastructure and there is no public mention of it. There are only a few rare case of player running into it. I would put it into the category of “really weird effect stuff that is hard to repeat consistently and almost never happens”. Those kinds of things make it hard for QA to document steps to reproduce it and even analyze it.
Even if something is a known bug, Blizzard does not give the GMs tools to fix it for individual users except in very very rare cases. You don’t want customer support mucking with game changes, generally speaking. It tends to make things worse given they are not coders, developers, etc. When the Devs do patch an actual bug, any manual changes done before that can make things much worse.
Correct. They don’t give game hints. Many many many things in a game as large and complex as WoW, are related to quests, phasing, etc. They do not help players sort that out.
Yes. You will be told to utilize community resources such as asking other players for game hints, or using a resource like Wowhead.
If it is actually a Bug, then that is also generally out of the GMs hands. Again, the proper way to report bugs is through the in-game tool or the Bug Report forum. GMs (tickets) don’t fix bugs.
You can read a lot more about what GMs can, and can’t, do in this thread. Sometimes players expect GMs to be able to just do anything they want, but that is far from true. They are very limited by tools and policies.