(Worth to add that in both cases the first error message regarding 'Vepar_Impact' always comes up at Freespace startup. Others appeared at mission load.) As you can see, despite of these minor errors mission 8 was completed successfully and without any problems: I was even not aware of these errors in standard not-debug mode at that time.
What troubles me with mission 14/2 crash is it's severity -- it's a program crash. Could it be something with SCP engine itself in the context of this particular mission? If I need to provide additional diagnostic information, I'd like to do that, but I'm not aware what may be relevant.
Yes, I don't think those warnings have anything to do with it. They're just minor glitches in the media VPs.
I have had people bring up this crash on commit issue once or twice earlier, but on different missions. It's most likely the result of buggy pilot code in the current 3.6.9 builds, which can affect any campaign. Does it occur every time you try it? Is the other crash with the freighters jumping out also repeatable?
As a last resort, you can create a new pilot, hit ctrl-shift-s in the mission simulator window to skip to that mission and just play the rest of the campaign through there. Some of the campaign features won't fully work (mainly that the stats/scores will be discarded and the mission 15/17 connection won't work), but it will still be mostly fine. Alternatively, I could give you a pilot I have that starts at mission 14, although you will need to reconfigure your settings in it manually.