Wondering if my protective diode is sufficent
The protection looks adequate but the If for the LEDs looks sub-optimal with 3 pots. Did you want it as a dimmer?

What is the purpose of the light sensing fan?  Why do you have so many pots? 

Why not use the LED series R to ADJ to regulate as a CC source. 

Unlike the LM317 which uses 1.25V referenced to Vout (non-inverting) this ADJ input is inverting with Vref=1.275V.  So to design a CC LED regulator move the Rs to the ground side and choose a ground side LED Rs for If*Rs=1.275 V for the desired the LED forward current.  With 12V-9V, you would have had a ~3V drop, now using the LM2941 as a current regulator, you expect a 1.275V drop on the ground side series R and thus a slightly greater drop on the LM2941 to drive three LED's with constant current.  If power Pd is an issue in IC, then adding another Rs to dump 1.5W can be done.