Delta Squadron w/Proton Rockets

Soontir Fel w/PTL

Academy Pilot x3

Is this a viable list?

The TIE defender only gets one die out of a Proton Rocket.

Attack (Focus): Discard this card to perform this attack.

You may roll additional attack dice equal to your agility value, to a maximum of 3 additional dice.

Defenders have 3 agility why would would they only get one die?

Relative to its primary weapon attack. Proton rockets are unmodified so all they've got going for them is more dice.

Delta Squadron w/Proton Rockets

Soontir Fel w/PTL

Academy Pilot x3

Is this a viable list?

Besides what TIE Pilot mentions (paying 3 points for one extra die at R1), low PS pilots face two very big challenges with proton rockets. One, higher PS ships (the ones you probably actually want to hit) with boost/barrel roll can more easily escape out of R1. Also, since you're shooting last, your opponent is going to be able to focus you down and force you to choose between using that focus for defense or taking more damage.

I think that proton rockets are ideal on ships with movement options, high PS, and multiple actions.

In this case, I think an ion cannon would be a nice addition to the defender instead of a proton rocket.

Defenders don't need protons as much as A-Wings (and TIEs-Advanced) do. They have 4 attack at R-1, so losing your focus for a 5th die is actually less average damage for you for that shot, unless you are also target locked.

I prefer a Ion Cannon for those 3 points: At long range, you can paralyze them, to let your entire team collapse on them the following turn. It also keeps them in your sights on a continual Koiogran chain in the end-game.

You don't lose your focus when you fire a proton rocket. You just need a focus to fire it.

Apart from that condition, it's quite literally a five dice attack at Range 1.

I think that proton rockets are ideal on ships with movement options, high PS, and multiple actions.

Proton Rockets, requiring only a Focus to fire, are actually ideal on low PS ships. They can shoot at an enemy ship, even if that enemy ship moved into the firing range after you activated, unlike with Target Lock which requires that they be at Range 1-3 after you moved.

They're Range 1 only.

The proton rockets are brutal with a Tie Advanced however keep in mind you have to get it off. Using a low PS pilot with it there is a chance it will get popped before it can fire. Also We may have done this wrong today but my friend flying Gemmer had to use his focus to evade a fusillade of fire eliminating his chance to fire a proton rocket at Vader at point blank.

I think that proton rockets are ideal on ships with movement options, high PS, and multiple actions.

Proton Rockets, requiring only a Focus to fire, are actually ideal on low PS ships. They can shoot at an enemy ship, even if that enemy ship moved into the firing range after you activated, unlike with Target Lock which requires that they be at Range 1-3 after you moved.

Better than other missiles for low PS pilots in many ways, sure, but that's not the same thing as ideal .

The proton rockets are brutal with a Tie Advanced however keep in mind you have to get it off. Using a low PS pilot with it there is a chance it will get popped before it can fire. Also We may have done this wrong today but my friend flying Gemmer had to use his focus to evade a fusillade of fire eliminating his chance to fire a proton rocket at Vader at point blank.

You did it correctly -- it's one of the flaws I pointed out regarding lower PS and the dual purpose of focus.

You only spend the token in question if the card specifies that. Homing Missiles and Proton Rockets do not expire the token, so the pilot can spend her focus to modify the Proton Rocket dice.