The Longhammer XL for Flat Head Nails upto 3 inch Long Nail Punch Nailer Driver Peashooter Nails where your hammer won't reach

Wouldn't this tool also work for driving nails back when pulling nails out of used lumber?

I know that it says three inch but is it possible for three and a half inch to work?

Will this work with roofing nails?

Can this be used to sink nails in deck boards that are pulling out over time? I have a bad back and need to sink a lot of nail heads while standing up