Yes it works perfectly
No, nails must match the angle of the magazine.
Sank over three hundred 1.5" nails, in pine, and battery was about 50% used.
If it is reconditioned the description will say so, and will have a lower price because of that. Otherwise it is new.
1.25" is the minimum.
The specs say that the nailer weighs 6.3 pounds. I believe that is without the battery, which would add maybe a pound more depending on the battery size.
No, 18 gauge nails will not work in this nailer.