Would my hand go numb, the back of my shoulder be in constant pain? esp to touch?(if torn) i can not lift stretch, or put behind back. i have spurs.

Partially correct: A torn rotator cuff or osteophytes/spurs in the shoulder would restrict your motion, lifting ability and cause pain but not numbness in your hand. Numbness in your hand can be a pinched nerve in your neck (from a disc or spur) or in your arm or wrist like carpal tunnel syndrome. See your rehab doctor for a diagnosis and proper treatment to avoid a frozen shoulder, wasted muscles or complete tear.