You need a fire-control to fire a missile. But you can have a 0.1HS fire-control to fire at any way-point in a system, so it would essentially be as firing without a fire-control.
This whole thing is kind of dumb that we have to do these calculations in order to fire missiles with sensors. If we like to fire on an echo we should be able to do that and the game should do the trajectory calculation for us. We should also be able to build missiles with or without a datalink connection. That is, missiles that can be communicated with and changed during flight or missiles that are just fired at a point and who then use their own sensors to find a target. Although, missile without a datalink should start finding a target not only at the destination but after a certain distance travelled which you set when firing the missile.
I think this would all be pretty simple changes to the game.
If you have a passive contact and a missile with a data-link you should be able to guide it into the vicinity of that target, but that missile would need to rely on its own sensors to actually strike the target. You only use the fire-control to guide the missile and make corrections if and when the passive contact make any significant course changes.
If you know the trajectory and speed of the target when you fire a missile the game should automatically be able to create a way-point at the potential intercept point.
If you have no data-link to the missile it will go wherever you tell it to go and will use its own sensors to find a target along the way, it will activate after a certain amount of time stated by you when it is fired.
If you have a data-link you can alter the missiles target point at any time, even switching target if you like. The game should automatically respawn missile way-points if a target changes course and there is an active data-link.
The data-link should be a small component you add to the missiles just like sensors, based on your active and EM sensitivity technology. The longer the range you want to be able to communicate with the missile the bigger this component will be. When the missile is outside this range it must rely on its own sensors and move towards the last know coordinate of the target.
I really believe these things should be in the game for realism sake. If you can guide a missile with an active sensor through a fire-control you can do the same with a passive contact.
There should also be active jamming options in the game, both for heat and EM interference. Not just passive ECM as we now have. You should be able to spoof on board sensors on missiles so they miss or detonate in the wrong place. Then you should be able to use ECCM on missiles to counter that etc...
The game should be more like
Command: modern air naval operations that is an awesome game, much like a modern version of Harpoon. Steve should take a look at that and steal some ideas of how space battles could be like using similar techniques in Aurora.