Missiles should be able to fire from both side and not restricted to firing arc

Agreed.A logic fail.

What is a lock-on fire and forgot system?

soundland wrote:

What is a lock-on fire and forgot system?

Once the missile/torpedo has locked and been fired, it no longer requires any input from the ship to keep the target locked and be guided to it.

For an example, laser guided needs the ship to actively "paint" the target with a laser so the missile knows where to fly. There are also wire guided and radar guided that works in the same way.

Hope that helpes :)

I agree to some point, it isn't practical in a way that it first has to be launched in the wrong direction, and the arch and fly around the bow of the ship to the intended target. 

If implemented i suggest a strong disadvantage for the missiles/topedoes lauched from the "wrong" side.