[250.124(A)]. Those provided in drawout equipment
or attachment plugs (and mating plugs and receptacles) must be
first-make, last-break unless interlocks preclude energization
without grounding (bonding) continuity.
[250.124(B)]. Yes, but only if opening the switch
disconnects all sources of energy.
[250.126]. A green screw (not readily removable),
green hex nut, or green pressure wire connector.
[250.126]. The entrance hole must be marked with
the word green or ground, the letters G or GR, or by a distinctive
[Table 250.122]. Zero. The minimum sized
Equipment Grounding Conductor is 14 AWG. It can accommodate a 15A
circuit. If you had a mix of 15A and 20A circuits, it would make
sense to use just the larger EGC (#12) or if you have high harmonics
use a #10 EGC.