Ah the ol "its not a problem for me, therefore it must not be a problem" mantra that I see so much on these forums.
In the 13 years I've worked as a software engineer, I consider a release "stable" when it can completely pass regression testing of all core functionality AND perform any new functionality without error aside from the minor bugs here and there. As you may have noticed above, I gave you 4 situations where core functionality is broken completely and it's not broken just for me. There are plenty on this forum who have the same problem, just read the threads.
What threads???
The only ones that have activity are the "App Failure List" for beta 4 and beta 5.
Your are the one that should be reading more threads and see that for almost everyone beta 6 it's been good, beta 6 could easily be the one prior the GM, if not, I don't think it will feel much different than beta 7 if it comes out.