While gun nuts always works on any shot you take, it guarantees a very low bonus on any firearm, too low to be interesting, even with specialization: for example, any special shot you can get with a feat (point shot, critical and so on) gives out an incredibly larger bonus than gun nuts, and then you should stack on top of that, that you can also increase those shots damage by using smart goggles and similar devices.
To be of any usefulness, gun nuts should have a way better capacity with specialization, for example by giving both low and high damage bonus for each point you put in.
Skinner is mostly worthless, thou iirc items you make with that leather values are better, and they sell for more money the last time i've checked this...overall, not worth: i think that anything short of metal armor is a lot less useful as armor, and while at least riot and tac vest have their "specializations" and useful for something, leather is just worthless for basically any build. Want to use leather? it's because you need to keep armor penality low, but to be even partially efficient, a leather armor need to have some additions and need to be high ql good leather, means you will end up getting the same armor penalty of a basic riot armor (20 ap) or basic tac vest (15 ap), so...it just does not make sense.
