Unless it's got AAA beams or something similarly silly, it's not going to be that much of a threat. With the mobility advantage of a light fighter you essentially have total control over the fight with a heavy bomber and can pick and choose the optimal approach and engage/disengage at will.
It's not that easy, really. You'd have to get the bomber in time, before it reaches its target, and, at some point, you'll have to intercept torpedoes. In The Zelos' case, I can ensure you that it's very difficult to cripple 4-5 of them before they destroy their target. Add their subspace torpedoes to the equation and things will get even worse. 
You still have yet to demonstrate how these flying bricks are a threat
to the player. Historical strategic bombers were devastatingly effective against the buildings and cities they attacked, and often appeared in such massive waves (
969 bombers participated in one bombing raid on Tokyo) that intercepting them all was truly impossible. However, the bombers always sustained massive casualties if the attacking force did not have total air superiority, and rarely inflicted significant casualties on enemy fighters without the help of escorts, regardless of their defensive armament and armor, because such defensive features are not and can never be a substitute for the mobility that makes a fighter a fighter. In FS2 and mods we seem the same pattern--sufficiently numerous and tough bombers can create a "the bomber will always get through" effect where you can never prevent their target from being damaged, but the bombers cannot effectively deter interception without escorts, no matter how heavily armed they are. The deck is
always stacked in the fighters' favor.
