No. Use a meter with a microfarad scale to measure its capacitance. Lacking that discharge it first by shorting across the terminals, then use the resistance scale. Hold the probes on the terminals and the resistance should rise as the capacitor stores the charge. Also test for continuity from the terminals to the capacitor case. There should be no continuity.
The proper way to discharge a capacitor is with a resistor i forget what ohm rating but i think one off an old start cap will work. And from what ive been taught capacitors dont increase voltage they help smooth out the voltage drop in AC cycles witch is why their not needed for three phase. So no i dont think its possible to check with voltage
The capacitor has no "output voltage " you would be reading back emf voltage of motor and that alone does not tell
You mfd. However there is a formula to use two parameters and determine mfd of said capacitor.