He can only shoot energy if he had absorbed it. His powers would be useless in a fight vs a melee opponent. Even if he had some energy stored up, its finite and he could expel it all in one blast, effectively leaving him vulnerable. The guns were a safety precaution that always made sense.
To your second point, he was part of the mutant circuit in X-Corp that was tasked with generating power to activate the Ionoshphere Bandwidth Generator