Choosing the correct power supply for my stepper motor (and other questions)

Other Hardware Motors, Mechanics, Power and CNC
11

i am powering my arduino through the 12V jack, 10 should be doable.

I agree. If you are supplying 12V, the regulator must drop 7V (12-5) so to stay under 1W dissipation there is about 150mA, total, available from the regulator.