You´re right, the Orion doesn't aim when shooting the beam from the forward turret.
But, I 've open your archangel POF model in Modelview, and edited.
First of all, I know nothing of modeling, so what I'm about to say might be wrong, but it work (the turret actually aims the target)
I selected the turret label - gun turret, and in the turret02 option, I 've changed the rotational submodel from turret02 to turretarm02.
Then saved the model, and ..... that's it!!!! Now, when the turret shoots its beam (for testing, I've changed to LRBBLue in the Ships.tbl, I might leave it like that) it turns in order to aim the target!!!!!!
Is this just coincidence, or is this well done?
For the not shooting problem, thanks!!!!, It was the distance, as soon as the engaging ship gets closer, the Archangel shoots its beams!!!!