The mislabeling of your videoports is a driver issue, there is not much you can do about that except a bugreport on launchpad.
But the fact that pulseaudio constantly "forgets" your choice of default audio device is solvable
Check this link:
The reason for this unwanted behaviour is probably this:
Switching to HDMI-audio when inserting a HDMI connector is considered user friendly. On several forums people have asked for this.
Personally I deem it user hostile, considering the arcane overrides one has to apply to stop the machine from doing things one didn't ask for in the first place. But yeah, sign of the times: Automagic for the people.
At least in Linux we still can change, in our own setups, what we don't like.
(at least Ubuntu-MATE delivers me the freedom and ease-of-use to do that)