(note this is not compleate code)I have an idea for beams mapped onto .pof file instead of just the texture. 
1) It includes loading a "pof" every time the beam is fired
      Pof_Beam = model_load( "Pofbeam.pof", NULL, NULL );
      Assert(PofBeam>-1);
2) texturing it with the default texture
         int bitmap_num = pm->original_textures[j];
(i think the thruster textures are defined a bit like this)
3) Scaling it using a methord simular to scaling thrusters
4) making it translucant like the wormhole
I think i can do steps 1 and 2 but i am stuck after that, Programmers i need your help. Who am i kidding i am not skilled enuff to so this this is a major mod, but the info could be useful for someone who knows what they are doing.
Things I Searched  for: 
 model_set_thrust
 beam_type_d_move
 Subspace_model_inner  = very helpfull (texturing and loading models)
need to find out: 
 how to make tha damn beam
 How to make the textures translucant
 how to assign a pof file to each level of beam