First, the 09/23-07 dev version seems to work alright, at least I haven't encountered any bugs yet.
Anyway, I think the plasma weapons should be changed. It seems that pistol and rifle is unuseable and blaster is extremely overpowered, especially its range and the damage from spray.
I changed this for having more fun myself, to prevent getting utterly destroyed as soon as the aliens get blasters. I know it is not at all realistic to add gravity to the plasma blaster "Ball", so i didn't, though it was a lot of fun when it was.
Remember, I don't know how it is supposed to be like, I have no expirience writing this stuff right so it is only to show my opinion. If anyone also thinks it should be chaged please try it, come up with ideas, then maybe some people can make a "real" rewritten/corrected file that could be added.
...Old links...