Weapon-specific-ness of pirate skills?

All I know is that yes, Somersault Kick can be used with a gun.

EDIT: So if you used no weapon, would the damage be based on ATT from your cape/shoes/gloves or would it do a set number (1, maybe?) all the time?

Your range, and thus your damage, is always based on your total WA, Str, Dex, and Mastery

In first job, you could have a godly Stars and Stripes and a godly Attack Shield and tear monster apart