I understand the concerns about agility and I will do something to address it. I rarely reach AM levels in my games so it hasn't been on my radar as much as it should have. I think I may need a different mechanic to replace agility but haven't decided how to handle it. I will also look at EW for missiles.
Plus, once I start running a campaign I will see how the theory works in practice. If there are problem, I will change it.
Sorry to bring up an old comment but I was looking through the thread and I had some feedback in this issue. As pointed out agility has an almost exponential effect on AMM efficiency since Agility don't do anything for missile defense and speed is what mostly define missile defense aside from ECM now as well in a different way.
But... when we look at missiles in real life there is a similar war going on between agile or speed as defense for missiles. I don't think any of them has won that fight yet as both have merits.
My suggestion would be to make agility on offensive missiles act as defense against enemy missiles but serve no purpose against beam attacks. The reasoning being that the agility is not quick enough to avoid a laser or Gauss shot at close range.
So... speed and Agility would be two separate defensive mechanisms and don't directly add to a missiles chance to intercept or hit something.
Now you could add agility to everything and use the same rules for missiles and ships. The heavier an object is the more space is needed for each point of agility thus a small missile need very little internal speed for agility and a large 10.000t ship need allot more space for internal integrity to conduct evasive maneuvers against missiles but you could potentially add some Agility to ships to reduce the chance to hit them... especially useful on slower ships.
This would also fix the current problem and add some more interesting things to equip things like fighters and ships with. It will also not make agility overpowered at intercepting missiles as you gain technology as you also use it to avoid missiles.
For offensive missiles agility will be useful to avoid enemy missiles but will do nothing against Beam PD, so you can't go nuts on it which will still make AMM slightly more efficient in the use of Agility.
You can also make small Interceptor fighters really good at dodging incoming missiles which can be interesting in a anti-fighter or space superiority role.
You could just make it something simple such as 5p Agility in the AMM versus 3p Agility on the ASM means 3/5 = 60% chance of avoiding a hit if the missile hit due to speed. Of course the balance would then be how easy it is to hit through speed or how to balance it.