If there is a problem, its not specific to Tie Bombers - It's with both bombers.
It's insane that with EITHER team, with a bomber, I consistently end matches with as top 1 or 2 in player kills AND capital ship damage. That is nuts (not to mention boring b/c why play other classes?). Bombers are plenty slow enough that they can't dogfight... but it's not about dogfighting, it's about being able to melt any other class with their chain gun anywhere under 1000m.
Don't kill the survivability or maneuverability, adjust their insane gun to be less effective against fighters.
Honestly, I don't think they should be nerfed at all. They aren't really game breaking. Imbalance makes things interesting anyhow. IMO games become bland and uninspired when things are nerfed to a state of "perfect balance" in an attempt to appease every single part of the player base.
It's like a plain rice-cake... or maybe it's like taking a peperoni pizza - shaving the peperoni into a fine powder and sprinkling it over the whole pizza to ensure every bite has the same amount of peperoni. Or hell, just puree the whole pizza and drink it. Perfectly balanced is like drinking your pizza.