Sorry about the delayed reply. The dwarf shooters have a real assortment of weapons - crossbow, blunderbus, bow, which is great in the context of a fantasy army, but it does cause a bit of a delema in terms of A1 and A2 armour protecton from shooting. I have followed the lead of others on this one, opted for the middle ground and classified Dwarf shooters as crossbow armed. This seems fair in that A2 protection reduced to A1 and A1 to 0 reflects the mixed nature and therefore effect of their mixed hand held weapons on armoured targets.
Yes, the dwarf armoured cars can move and shoot unlike ordinary artillery. This gives them the ability to launch very effective surprise attacks and they also have the option of using the 'Hold Fire' order to fire in their oponents game turn.