This may have been answered elsewhere, or it may just be as straightforward as it says on the card, but..

My friend and I had a game last weekend and I was flying a Tie/D with Ion cannon, I shot at a ship with my Ion cannon and hit it for its last hull point.

The title says that I can perform a primary weapon attack after the attack with the equipped cannon, I assumed I could shoot again at a different target, however my friend said the attack must be against the same target.

Who is correct?

The cArd does not say you have to target the same ship with the primary. So you are right.

After reading this post I just want to check

Can I shoot Biggs with TB and barrel role him out of arc the fire primery weapon at someone else?

After reading this post I just want to check

Can I shoot Biggs with TB and barrel role him out of arc the fire primery weapon at someone else?

Yes. It's a completely new attack and Biggs is no longer a valid target if he's not in the Defender's arc anymore, so even if he's still in range 1 of someone who is his ability doesn't trigger.

Thanks