I don't think you'll get the results you want by changing the BS shields like that though. Capital ships well and truely should be the monstrous terrors we all want them to be. In other words they should be augmented and then their usage limited artificially on the server, perhaps like Panzer says making BS licenses Admin distributed. I don't think making cap ships slightly less dangerous will affect fighter usage one wit.
I see the bombers themselves as the real problem. Look at Piracy. Arguably, piracy makes the most demands on a ship's ability. You must fly the most versatile ship possible when you pirate alone. You have to be able to do massive amounts of damage in a short period of time, be fast enough to overtake a variety of targets on thrust while at the same time be able to defend yourself against lawfuls. The ship of choice for piracy is unmistakably the bomber, no other craft offers that combination of manueverability, speed, versatility and firepower. The only people pirating in VHFs are sorry masochistic purists like myself who like the 'sport' of it. Then you even have whole lawful battlegroups made up of nothing but cap ships and bombers...they obviously don't see a need to have a fighter in the mix...and they are right.
There's a battle of rhetoric surrounding the bomber that should be aired out. Current wisdom places the bomber in the same ship class as the VHF (LF, HF, VHF and bomber are all considered 'fighters' according to ID limitations.) This was the first mistake made on the road to the ultra uber bomber, we equated the bomber to a very heavy fighter which of course led people to believe that they could put fighter guns on the bomber, effectively making it a very very very heavy fighter. Then we made these bombers the same size as the fighters and (originally) made them almost as maneuverable. All of these ghastly unbalancing options became common place, de-facto standards for bomber configuration. People fell in love with the ship and bemoaned every bomber nerfing the same way they are fretting away in this topic. And we're really just putting ourselves through a lot of flames to make uselessly small changes to a fundamentally unbalanced ship. All of these petty little arguments we have about pilot skill and how not to get yourself killed while flying fighter on bomber simply reinforce this ridiculous notion that the bomber is only slightly unbalanced, or that there are only a few uber bombers in the mix that need to be toned down.
Bombers need to be more specialized to their role. Right now with 4 class 10 guns they make better than mediocre fighters, and that just shouldn't be. A bomber's one and only credible weapon should be their payload. They should sacrifice much in terms of defensive capability in order to deliver that payload. The payload should be of such a magnitude as to justify the risk they take.
Solution:
-increase the yield of the supernova and nova torpedos to something that would be almost catastrophic to an unshielded battleship.
-optimize the size of the bombers, i.e. no more 'light' or small bombers.
-remove elite fighter guns from the bombers entirely, put guns or turrets on them such as they would need to complete missions effectively but be useless against a VHF. class 7 guns or less in other words. And no missles.
**There is an interesting option with bombers not explored yet. Why not increase their thrust speed to something faster than normal, like 250. Give them the extra speed to in effect make them 'dive bombers.' You could compensate for the increased speed by further decreasing their maneuverability (much like WW2 dive bombers that were slow turners but fast climbers and divers.) This would of course mean the supernova/nova speed would have to be decreased to compensate.**