Yea, I think we all saw where you were going with the card, but I think there's too many reasons why you can't really allow people to shoot during the maneuver segment. Sable probably hit the worst possible one, but the other effect is you can just use moving first to your advantage when the opposing ships haven't even had a chance to move or take a defensive action, which is too powerful. I strip Lukes shields in the prior turn then move to range 1 and immediately attack while he can't move away or otherwise defend himself? a little too much. Saber Squadron Pilotss would abuse the crap out of this. Hrr Hrr 4 dice before you can do anything....The big difference i see between this and a mine/bomb is that a bomb can be avoided. A good pilot can look at your bomber card and remember "This guy has a prox mine so I'm not going to fly through his backwash". With a shot, there is no way to avoid consistently being in someones arc and therefore avoid the damage. Especially when they get to fly first.
But if something like this were done i would agree that it needs to be further restricted. Maybe resticted to particular types of ships or make it some sort of unique card (like squad leader), or discard after one use. Or some combination of those. I like this type of thinking though that tries to add more layers to the game and give more build options.
That's exactly what I was going for with this concept. I personally like the idea of making the activation phase less safe and/or more dynamic--to me, the thought of flying up on someone's rear and unleashing a surprise barrage before they're able to fly away is an exciting concept.
As I set it out in the OP, the ability has some relatively steep costs--it takes up an EPT slot (which means you're really not jumping up that high in the PS rank with it; to me, the advantage has more to do with the fact you're making an attack in between movements and at a potentially opportune moment), it makes your attack 33% weaker (via not being able to focus for it, though you might be able to make some of this up via zooming to range 1) and takes up two squad building points. Not opposed to balancing it further with a mandatory discard or something, but just wanted to point out the price you're already paying.
bombs and mines allow for this now (attack in the action phase)... I don't think that's the broken aspect here.. multi use is really the problem I have.. that's all..