OK, so if I put kallus, quad-lasers, and flechette missiles on 1 ship, what effect does the toggling of the activation slider have?

Would it immediately end that fighters activation, or just be a waste of a hit/CRIT icon?

It is wasted on a Counter Attack.

There is nothing to state that the Squadron would not finish its activation. Only that its slider would be toggled... Which would happen at the end of its activation anyway.

• A squadron cannot activate if the color and icon of its activation slider do not match the initiative token

The only check on the activation slider is before it activates. Once its activated, then its activated, and doing its activation.

I am not sure. The activation slider is not toggle until the end of the activation and you can't activate a squadron if its activation slider doesn't have the same colour than the round but your are not activating the squadron you already activate it before the slider changed so I would say that the squadron end its activation normally.

At the very end you would prevent the squadron for moving if it didn't move not more. It is a thing of course.

It is wasted on a Counter Attack.

There is nothing to state that the Squadron would not finish its activation. Only that its slider would be toggled... Which would happen at the end of its activation anyway.

• A squadron cannot activate if the color and icon of its activation slider do not match the initiative token

The only check on the activation slider is before it activates. Once its activated, then its activated, and doing its activation.

Drasnighta'd!!! XD