Problems with the boss
I have a bit of a different perspective w/ #6... The vast majority of cases I've seen of people seriously not getting along with the boss have involved 1) an employee who was truly an incompetent, horrible person or 2) unlawful employment discrimination, sexual harassment, and or other unlawful activity by the employer.
In the case of the latter, talking with the boss about it seems to be inviting even more trouble -- especially in my experience as an attorney who has dealt with these matters.
And in the case of the former -- well, a truly horrible, incompetent employee isn't going to think that they're the problem, anyway...and they'll be fired soon enough.