Suitable protection for elements on power line
Depends on what the voltage source is. If the voltage source can't source enough current, when the motor is turned on, the LED's will dim or switch off. To prevent this put a bypass capacitor on the Vcc to ground.

The motor needs a flyback diode on it to prevent inductive kickback. Because the darlingon pair has a bypass diode, any overvoltage produced by the motor will be put back to Vcc. 

The diodes should look like one of these configurations: