Can somebody tell me ?

Yes - forget about that site - there you can only ask with no answers, cry about no support, read spammers posts and imagine what else could be done, but no one will read that. Go to http://battlestations.eu like other modders and try in that place.

Hmm well afaik you cant change vehicle names easily, i'm leaning towards saying that it may be possible, but with my experience of the hardcoded (&#@%*%@#&*%@ rage) methods BSP uses, it will either be very hard or impossible.

I believe that if the file is empty, its a redundant file (try opening 1_usn_09SOLO.mpak instead), and no, you cant use it to patch over the scenario, or at least there is no lexicon for the file topology that you can edit.

Your question did not go unnoticed by BSMmodHQ and an answer was sent to you yesterday. Hope it helped you with the issue.