2) AFAIK Heavy Ballistic Integration is hardcoded. Check the hullmod that gives you a makeshift flight deck though
Heavy Ballistics Integration is not especially hardcoded, though if you want a new dynamic stat for a SPECIFIC fighter (instead of all fighters, or bombers, or interceptors, or support fighters, or whatever) then you will have to do some more code.
You -might- be able to iterate through the weapons mounted on a ship via BaseHullMod.applyEffectsAfterShipCreation() but I'm unsure whether that is run on the outfitting screen. If it's not, then it's pretty useless changing the OP costs in it
As a somewhat hacky solution, you could (if you want to be exclusive about it) warn players that any fighter that ISN'T the SpcSnowflake Mk4 will be massively penalized by installing said hullmod, and then just reduce the cost of all fighters if it's installed, and use an override on BaseHullMod.applyEffectsAfterShipCreation() and/or BaseHullMod.applyEffectsToFighterSpawnedByShip() to check whether the fighters are the correct type and nerf them if not, but this does seem rather inelegant.