Comments should be commented out by:
; This is a comment
Or
;; This is also a comment, but the second semicolon makes no difference
The ND is short for No Dim, which was FS2's origional hackish support of lights. Basically, it's an RGB value of what color to not dim as the ships were rendered, so that they would glow in the darkness. These are left out for good reason, as we now have magical glow maps.
The weapons problems probably aren't the problem. And where did you get your ships table? All I can suggest is a thorough examination of each entry, or perhaps the deletion of all description fields. :V: Actually had this problem too- with one of their missions, they accidentally put a semicolon in the briefing stage, and didn't realize the semicolon was the problem, so they just ended up deleting it. In all honesty, that's kind of difficult given your lack of expertise with the ships.tbl.