Yes, but 1/2 inch id is the normal size for tub and shower valves.
This tubing is soft copper and is not designed for sharkbite push fit fittings. Compression fittings are the correct fittings for this.
Yes , when installed properly
1/2" OD - 3/8" ID = 1/8" difference. 2 walls, so each is 1/16" or 0.0625"
It is bendable by hand but not for tight bends. You could bend to the shape of hula-hoop by hand, but any bend much smaller than that and you will need bending tools.
It's safe to use with potable water... if that's what you're aiming at. Notice also, there is no "California hazard warning" listed as with most all valves, pipes and such that contain trace or minor amounts of lead. Personally, I use it for making wort-chillers, both immersion and convoluted.