Eve is a great game - but i am still missing some kind of management for the Planet Stuff.
Why you cant place a Settlement on the City near your industrial stuff and then, depending on their Planet, you need to deliever food,produce food while the citizen itself boost your PI or produce some other regular products which you need to gain a better ISK income per day and so on.
On the other hand you should be able to do some Strategic Battle with it when you could set an Pilot as Governor for the happening fight and he has to outsmart the enemy player.
So creating Soldiers, Civiliance, Marines(on the Planet) or Clones and Special Troops (on Stations) to overwhelm and conquer a planet which is hold by a corporation with some kind of planning you can see in other grand strategy games.
Also if you see your planet is under attack: You could still destroy the attacking ship (which, after being destroyed stop the attack at all) and adding more stuff to build like tanks, fighter, armor for the units, weapons for the units, armor for the units and many more stuff which could add more depth into the game.