Is it a good idea to use the motor voltage as a source for a logic regulated voltage?
Make sure you have enough overhead on the PSU to drive the motor so it can maintain the desired voltage.
Additionally I'd increase the capacitor on the input of the 5V regulator to minimize ripple. As long as you're just using the 5V for logic I don't see a big issue, if you use it to generate reference voltages for high precision measurements the story would be different.