Missiles should accelerate at a faster speed than the ship they are shot from
Currently in Space Engineers when a missile is fired, it is shot from a set speed. Meaning it does not accelerate or increase in speed when shot. So when you are going at the max speed(100 m/s) in the game, missiles become useless to fire, as you will either hit yourself or they will easily miss their target.
If missiles simply scaled up to the speed that the grid was already traveling to than you would rarely have instances of accidental misfires when the missiles can simply travel at a faster speed.
(Also yes, at the moment certain speed mods can travel faster than missiles meaning you can hit yourself)