All of the laser weapons are bull**** science wise: it's only in atmospehere or water where the high energy beam would have to ionise the environment where you could see the beams.
Even then these would be a long continous stream from the barrel to the target - just like the beam weapons in FS.
A laser/electro-magnetic wave weapon would be invisible in space. All you would notice is the flare of the gun barrels and the shimmer of the heat sinks on the attacker and the sudden melt in the receivers armor. Furthermore these would be effectivly point-hit weapons, so anything in the target reticle would immediately get hit. A miss is still posible though since it takes time to charge the guns, and in reality the weapons would have to be actually aimed by computers, since some sort of adjustable convergence would be more than necessary - especially since the very beam you fire should be focused on the target as well or it will have minimal effect.
Beam weapons on the other hand look apropiate - they fire high powered plasma - BUT although you should be able to see it, this plasma should behave like a projectile, so unless it is fired from a very powerfull accelerator coil, it would have a little tendancy curve as a flamthrower's flame does.
As for the sound in space: Radio interference. High powered fusion engines, as well as high energy electro-magnetic equipment create readio noise that can interfere with the frequencies on which your flighradio operate.
This is actually a "welcome" fault in the system since it helps the pilot to give him more bearings.
