Long range would be sacrificed in return for firepower. The station would have to be very bulky and armed to the teeth to be able to penetrate enemy territory. As for AI game logic, I'm no modder so I really can't think of anything sorry.
If the deathstar proves to be a bit too challanging, you could also try this Galaxy gun, a less known super weapon of the empire. http://starwars.wikia.com/wiki/Galaxy_Gun
Meshes will be hard to come by, you can always ask eviljedi if he ever worked with this type of super weapon.
It's the same principle of the TEC gun, but it would wipe out the planet completely (longer recharge for balance).
It IS the hardest thing, and so far you've managed to keep it flowing, unlike most mods i've tried.