The devs here are normally very hands on, I have to admit.
Since my Linux days (which is 16 months only) I always had some or other problem with burning cds or dvds. However, even so I don't use KDE but Gnome and Xfce/LXDE on lighter rigs, I always had to get K3b in order to make sure that a burn will not fail on me. Maybe it is a fluke - but K3b so far has not let me down - not once.
I am following your tries and tribulation and feel the pain for you. Something simple like that one just wants to work. The erratic way of the errors you encounter doesn't help with the find for solutions.
I still believe - reading through it again - you are dealing with an hardware issue. I will not commit to any further educated guesses so but wish you will find the culprit soon.