I have had good experience with "focused" fixed pulse lasers, although on large variant the increased piercing value might be wasted - check the long range mod for large and huge lasers, it probably provides higher overall damage output.
Also, if you can spare some power (probably not on a Vulture) burst lasers can deal slightly more damage than pulse with similar energy efficiency (DPE), and bursts also have the focused mod available.
Emissive special might be a good option on one of your pulse lasers since it will prevent NPCs going off scanner when they use heat sinks.
For shields, I found that around 500 MJ (with increased resistance) is enough to survive pretty much any 1 or 1 fight with NPCs. If you can get your shield that high, you don't really need any HRPs at all.
If you are limited by power consumption, consider using smaller (D or even E rated) shield boosters. With engineering, four E rated boosters can provide some serious shield boosts (both heavy duty and resistance modded) at very low weight and power consumption. I ended up using 4 boosters (I think it's 2xA and 2xD) on my DBX, which seem better than using chaff - shield boosters help against all incoming damage, while chaff is useless against some of the most dangerous weapons like PAs or rails.