Faaaaarrrr too hot. I would drop engine size, downgrade to SRM4 (tighter missile grouping anyway) and add in as many DHS as you can. The basic idea is great. The Blue-Beam Shotgun is very effective. LLas to tear everyone up at range and SRMs for that intimidation factor and mega-punch in close. Even better if you go 2x LLas, 2x MLas and throw a STD engine in. Then the SRM range becomes less of an issue as you are more survivable. Anyway, great basic idea, just needs some tweaking in execution to make it more viable per heat.
ER for range and Pulse/SRM for close combat... the heat efficiency says 25% still but without the ERs its 39%... also has the bonus of pulse/srm both on a 3.25sec cooldown so they will fire together every time... number of srm shots increased from 16.66 to 25, which is nice considering the tighter groupings its mainly splash damage that you are losing per shot...
I know the original heat efficiency is poor at 25% but you don't have to constantly fire all weapons. Fire ERLLs when you are at that range, only LLs when closer and then only SRMs when very close range. If you look at the weapons lab in smurfy and look only at the ERLLs, they have a heat efficiency of 71% and a sustainable dps of 3.01 which is pretty decent for 800m range shooting. At close range if you are only using the LLs and SRMs they have a heat efficiency of 38% with a sustainable dps of 6.17, fairly modest. The point is you are not supposed to use the ERLLs except when shooting at targets more than 600 or so meters.