Dreadnoughts should be, in my opinion, impregnable fortresses. While capital-class weapons would cause untold devastation, they would have such long recharge times to make them infeasible to use against much smaller ships. And if you felt like you could, perhaps, even delve into coding, then you could give the Dreadnoughts their Siege Mode ability from EVE as a system. This would double the range(making capital-class missiles, beam lasers and rail guns stretch across the map and make even blasters into modest sniper weapons), add some fraction(probably 25%) to damage, and either double shield efficiency(Caldari, Minmatar) or start an armor regeneration system(Amarr, Minmatar), but at the cost of constantly generating flux and causing the ship to be inable to move or turn.
Also, I still say you should turn the beam lasers into burst weapons, and make the pulse lasers shorter in duration but faster.
