Sylvain
I am very curious to see your new bird!
I think the light issue you have is different from dharris' one -yours is a bug in the exporter I faced it several times during the T-45 development, and it has shown on a Tomcat test build recently:
What happens to me is that I cannot delete any attach point after its creation - if I do, the catapult attach becomes a light, and possibly the other lights are screwed up, too. I was trying new A/b effect for the Tomcat but if I delete the attachpoints for the old ones the cat points become lights, the landing light is screwed and one of the red lights turned green.
I did not look into the .X for this issue - but you'll probably some mess there.
Worse than that, deleting the points and remaking them does not seem to work - the source is "screwed" and so will be all the later versions. I had to roll back to a previous save and keep the points.
dharris's issue is a different one IMHO - some users have lights where the cat point should be (launch bar working for all the other users). It is the first time I see it on the Tomcat, but those who had this issue in the Goshawk were all non-Acceleration users.