ok, so perusing my figures , I came across Gambit/Rouge duo, and they have a special power that lets them use force blast. the duo ability says that this character makes two combat attacks as free actions.

force blast: when this character hits with an attack, you may choose that it generates knock back . so it appears they will work together per the 2014 PAC. this is great and gives that figure new strategy ideas!!

any other powers or abilities I may have overlooked with duo attack??

Anything that works with an attack (of the type you are performing, ie close/ranged) will work.

Precision Strike, Steal Energy, and Super Strength are a few examples.

Would precision strike activate on both attacks?

Yes. It works every time you attack period.