I have just got the YT-2400 Expansion and I'm slightly confused.

Does the primary weapon (Printed on the ships card) have 360° arc?

When I buy a cannon upgrade such as the Heavy laser cannon does that replace my primary weapon stats and does it have 360° arc?

And if it does have 360° arc as either primary or secondary weapon what is the point in the outrider title card?

Thanks in advance for any help or links to answers

No - Turret Primary weapons allow you to shoot outside of your firing arc - they do not have a 360 arc

No - The cannon upgrade only works in your firing arc unless you equip the Outrider title - if you equip the Outrider title it allows you to fire the cannon weapon outside your firing arc - it does not give you a 360 arc.

The "firing outside your arc" phrasing is an important distinction to understand when it comes to game abilities that trigger when attackers / defenders are in / out of arc - i.e autothrusters - Tactician etc

So if I leave my primary weapon alone it can fire outside of its arc but if I buy the cannon upgrades I need to use outrider to gain the ability to fire outside of my arc?

Can I buy the Heavy Laser Cannon but still use my primary to fire outside of my arcs?

Your Primary Weapon is a Turret (2 red dice shooting 360 degrees), if you equip a cannon (I.e. HLC 4 dice) it shoots out of the printed firing arc at the front of the ships base only. You don't lose you primary in doing so it can still fire out of arc when you don't have an available shot with your cannon.

Yes to shoot the cannon upgrade 360 degrees requires the Outrider title & you do lose the primary weapon

Okay cool, so the only other thing is can you fire primary and secondary weapons in the same turn or is it just 1 weapon system per ship per combat phase?

Okay cool, so the only other thing is can you fire primary and secondary weapons in the same turn or is it just 1 weapon system per ship per combat phase?

Just 1 weapon per turn

(some cards making exception to this would be things like 'Gunner' crew, which allows a primary attack after missing 1st attack)