I expect that a rigid full size crowbar would work better on "tacks" driven into concrete which might really be stainless or monel steel nails - these are light prybars without the leverage you may need.
Lest than a pound
I suppose but I would be very careful as the pry bars are metal. I primarily use for molding and trim removal.
Yes it says made in the USA on all 3 bars.
Yes, very easy to use and with the 3 different sizes, it works for most tasks.
Yes, smaller sections. A larger pry bar might be better for flooring.
9 inches, 6 inches and 5 inches, apro.
don't know, probably not