You must balance the rotating parts, place the shutter over a screwdriver shaft and see where it stays still.If you are not satisfied with light intensities, you can always vary value of the 3 resistors that load the laser you can even force it a bit.Solder a jumper wire on the back of the center pin of the DC connector of the breadboard power supply to power the Arduino "Vin".DO NOT use the regulated 5V of the Arduino, RTC and sensor for the rest of the circuit, use different lines (this is always valid).