1 AP allows to do several steps instead of one. And, for example, running takes less APs than croach movement mode. However running mode has own disadvantages, while croach mode provides better hiding. The weapons are not balanced yet, but you can clearly trace main principles. Even pistol may be very useful in the game, because it takes less time to shoot, and some models have burst fire mode - three bullets per shot.
Shotguns are important too.
With respect to shot calculation, Tactics offers the unique opportunities. Like in previous Fallout series, burst mode is very unusual in Tactics . It is very dence and almost fatal in close combat. But if the distance is long, auto weapons mostly produces the wide area fire. The demo version arsenal is not too large, about 3 or 4 names from each weapon class.