This is something that seems quite clear to me but the problem is that i've 2 friends that doesn't think the same way as i do.

I fully understand english while my 2 friends doesn't and they are refering to the frensh version of the cards.

However, i don't own the ship (as i'm still not sure i want to buy such an ugly ship from the rebel TV show and new canon... except if i want / need to play it one day)

in the phantom text there's 2 effects

1) Allow the ghost to shoot from special firing arc

2) Allow the ghost to shoot with a turret at the end phase

For the (1) part, i might miss something as i didn't own the ship, but the way i get it is that, without the phantom docked, this special arc is used only for torpedo (but doesn't prevent from shooting torpedo from primary arc). I think that the question related to mechanics like outmanoeuver and this special arc is still unsolved, if i'm wrong, please correct me.

But the real question here is about the requirements. For me, there's only 1 requirement and it's :

1) While you (the Phantom) are docked

but my friends keep saying that

2) the ghost require to shoot from special firing arc in order to be authorised to shoot with the turret.

There's indeed a "an additionnal attack" that might be understood as a first attack requirementto get this turret attack.

However, i see the text a little bit like this :

While you are docked, the ghost can perform primary weapon attacks froms it's special firing arc.

Also, while you're docked, at the end phase, the ghost can perform a turret attack.

I believe that the text should use the word then if they wanted the special firing attack as a requirement.

While you are docked, the Ghost can perform primary weapon attacks from its special firing arc then, at the end of the Combat phase, it may perform an additional attack with an equipped turret. If it performs this attack, it cannot attack again this round.

Also, dispite the "an additionnal" wording, i think that we can shoot with the turret if we shoot from the special arc, the primary arc, with a turret or even if we didn't shoot at all (*). Am i right ?

* i think we might miss the opportunity because all the targets are out of range but a special after attack action (turr phennir) or a tractor beam attack might move the target in range to allow this end phase shot to be used.

I'd like to have as many people as possible to answer thoses questions since you're not official answer and it will give more value to the answer (allowing me to convince them (or my self)) if many people think the same way.

You're correct. The text says "While A is true, you can do B and C."

For the (1) part, i might miss something as i didn't own the ship, but the way i get it is that, without the phantom docked, this special arc is used only for torpedo (but doesn't prevent from shooting torpedo from primary arc). I think that the question related to mechanics like outmanoeuver and this special arc is still unsolved, if i'm wrong, please correct me.

I have not seen anything that says to not treat the special arc as an arc for the purposes of abilities that check for one. As long as an ability refers generically to "arc" the special arc should count. If something specifically refers to "primary arc" or "auxiliary arc" then the special arc does not qualify.

Lacking any rule to the contrary, applying the existing rules for generic arc requirements seems to be the logical choice.