Capital ships have a place in disco, and they attract new people as well as create activity.
I have a different take on how they should work, however.
Increase capship hull by 4-5 times. Make them a little slower, make their guns hard hitting with pretty explosions and all. Point being that a capship is only effective against other capships. Dreadnoughts would then be ships exclusively tasked with taking out each other.
Cruisers would be the bloody infantry with a little more anti-snub ability, not much though.
Gunboat would remain an effective anti-snub weapon.
As far as fighters go...reduce their hull, buff gun damage, remove AUs. Make fighter fights exciting, where one mistake could result in a glaring respawn screen. Increase their speed and turnrate as well.
Bombers would go the same way as fighters, quite slow compared to fighters, with less hull, but more powerful SNACs and Novas.