Actually, there is one way to make a beam weapon in EaW : the Accuser's Proton Beam ability, which draws a beam effect between the emitter bone and the target as defined by lightningeffects.xml.
The thing is that you can only have one beam per ship, and can't restrict its firing arc.
Also, all beams will look identical because they all use the same effect entry.
Still can't do slash beams.
Also, you can do a direct-fire beam via weapon model and very specific firing ranges, like that guy did to make the composite beams on the Clone Gunship thing. That only works on ground combat because the model actually extends past the target and into the "ground".
A FS1 mod for EaW would be entirely feasible though.
