Wouldnt it be better if you pressed a key that activates the missile's afterburners, after you've launched it.
This could prove successful for say if you're bombing a crusier and just as your bomb is entering the cruisers firing range, you could activate the afterburner and speed it up so the cruisers guns cant hit it as accurately, giving your bomb a better survivability rate. - (does this happen in FS2, "the faster something is, the harder it is to hit", asuming the gunner is AI)
Or how about a time delay activation sequence, - eg. if after, say 10 secs, after launch, you do NOT press the key to activate the afterburner, the missile automaticly activates it for you.