Given names often turned into family names when people were identified by their father's name. For example, the first name Ahrend developed into the family name Ahrends by adding a genitive s-ending, as in Ahrend's son. Examples: Ahrends, Burkhard, Wulff, Friedrich, Benz.
OK the definition you have used for crouching associates it with stooping (which on Wikipedia redirects to bowing. Squatting essentially involves bending at the knees and hips. If there is any bending at the waist (and maybe lowering of the head) then that is considered stooping.
Yes, but squatting shoulder width will train more muscle mass, and sumo squatting will train the muscles which 'operate' (to simplify it) at the wide stance, which incidentally is the stance which someone is likely able to squat the most*, due to leverages and range of motion.