Coming from the Warhammer 40,000 board game, it makes sense to me that the lasgun and laspistol are relatively humble weapons. However when it came to the laspistol, I wonder if things were taken too far, because shouldn't the Laspistol have a semiautomatic mode? Virtually every other pistol in the armory is semi-auto, aside from the hand cannon and revolver. Even the stub automatic can fire 3 shots. Surely the laspistol should have a semi-auto mode as well.
Thoughts?
In all the novels and games which I've seen, Las weapons are capable of full auto fire. Recently I've been readin The Hammer of the Emperor , and in several instances the Guardsmen (not Stormtroopers or Kasrkin, who wield Hellguns, but normal Guardsmen) "switch to full auto and spray a burst of las-blasts." Likewise, not just the Skitarii have a Hellgun that fires on full auto, according to all the non-RPG literature.
I would absolutely agree, but the solution in-game is easy enough. Just use the Inquisitor's Handbook and it's weapon tables to find whatever suits your idea of what laspistols should be, and swap them out. My opinion is that they should be Fury pistols with an extended range of 30 or 40 meters.
One thing to keep in mind is that the ROF need not be a 100% literal translation of how many shots you toss out, and that authors aren't bound to an RPG rulebook when writing their action scenes. Furthermore there are numerous marks of lasguns scattered through the FFG games, some of which have semi, and full auto modes.
Like someone above suggested, have a look at inquisitor's handbook. It has various marks of hellguns, lasguns, and laspistols intended for specific military roles and often have higher fire rates than the bog standard pattern in the core books.
Also of you have a nice tech priest, who's ordained enough to know the proper patterns and rites he could modify a lasgun's fire rate. Of course he might also call you a heretek for assuming that the omnissiah's sacred weapon patterns are insufficient in some way.
It's much like civilian model 'assault rifles' here in the real world. They take a military weapon and modify some internals and other parts to make it legal to own without special liscences. With the right tools, time, and know how some can be returned to their military specifications, others can't. The AK-47 and P-90 are examples of just such products.
And if you want to tweak las weapons even more, feel free to have a look at what my group did to lasguns: http://dark-heresy.wikispaces.com/Las+Weapons
I'd say that the best solution to a weapon whose stats you don't like is to simply offer an alternative pattern. There's a near limitless variety of even the ubiquitous lasgun in the Imperium thanks to all the different Forge Worlds and their different variations of STC-designs. I think the best example of this is the lasgun used by the Death Korps of Krieg. The Imperial Armour fluff describes them as having a much slower rate of fire, but each shot is proportionally stronger to compensate. This way, the Krieg troopers lasgun puts you more in mind of WWI-era bolt action rifles. Compare this to the Elysian Drop-Troopers lasgun, which has an ultra-modern bullpup design, and looks almost like a Steyr AUG - you could imagine they have a full auto mode but the individual shots are a bit weaker. It's really your call on that front.