With cluster missiles, I spend a charge for the attack, keep the target lock, do I have to spend an additional charge for the bonus attack. Does not say to, but it also says I can ignore the target lock requirement.

Yes, you spend another charge for the second attack. Cluster missiles lets you repeat the entire attack again except a) you no longer need a target lock and b) it must be against a different target. Otherwise, it's exactly the same as the first one.

It says "You may preform this attack again" that means starting from the top again which includes spending a charge. If it weren't a limit to only 1 bonus attack per round you could theoretically keep doing attacks until you ran out of charges.

Thanks

Separate but related question:

Does the 2nd attack need to still be in the shooting ship's front arc?

Someone was telling me that as long as it was 0-1 of the defender they could do the bonus attack against it even if it was out of arc, but that didn't sound right.

5 minutes ago, DTDanix said:

Separate but related question:

Does the 2nd attack need to still be in the shooting ship's front arc?

Someone was telling me that as long as it was 0-1 of the defender they could do the bonus attack against it even if it was out of arc, but that didn't sound right.

It's not. You still have to follow all the rules that define a normal cluster missile attack, so the second target must be in your firing arc at range 1-2.

And if you are a lucky guy and still have a token you can still modify the 2nd attack with focus or calculate or other (ship) ability I assume?

Yes.