Just a comment, but the "refire rate" of the weapons is irrelevant. This is the D20 system, not a FPS. The damage of the weapon and the to-hit modifiers represent the accuracy of the weapon, the power of the weapon and the refire rate.
In short, you would just be boosting the damage/to-hit due to the higher rate of fire, not actually firing more shots.
In case you weren't aware, the D20 system used here is almost the same as the Star Wars pen and paper RPG published by Wizards of the Coast. (The differences come from trying to translate a pen and paper system into the computer and account for "real time" turns, which aren't really "real time".)