How are you pulling the models from the game, or are you making them yourself? Ive wanted to pull the models for quite some time.
You do know sins doesnt support animations right? However you can work around that with particles. See the B5 mod for that.
I noticed that your nulls are pointing in offset angles. You do know sins only recognises nulls that point in a 2d plane. Ill try to explain it, because its hard to explain without showing you. Sins only supports firing arcs pointing forward, left, right, and back on a 2d plane. So your nulls should be facing 0 90 -90, and 180 degrees. The only "offset" nulls i saw were on the Kol battleships autocannons, and that seems to only effect the muzzle effects. Not the firing arc itself because it is still pointing in one of those main 4 angles. Sins firing arcs are broad, general, hardcoded, and cover 180 degrees in one of the four directions a null is pointing.
I did find out something interesting. If a null is facing normally it fires at targets "above" your ships no problem, but it rarely fires at targets below the ship. If you flip the null upside down like you do in Nexus modding. Then the null will behave just the same except it will fire at targets below normally, but rarely fire at targets above you.
Sins is based on 2d combat, but the ships move somewhat in 3d which is why the firing arcs are so broad. With the dynamic movement of entrenchment the flipped nulls make things more interesting. Just some FYI
I am interested in this, but i cant help much because of my own project. I can however give advise, and tell you what i know of sins modding.