Quoted from Xtraball:Enter DumbAss,
Suggestions for @DumbAss:
1) Put vent holes in the PCB so those ?2W? led resistors can breath / cool better. Right under the resistors so convection heating of the resistors draws cool air up from behind the board. Looking at that layout; it should be very easy to put large holes under those resistors. The side effect is those resistors should stay cool; and reduce solder joint cracking.
YDnHO[1] (resized).jpg
2) If you're laying those power resistors directly on the PCB; don't. Put at least a 10th of an inch between the PCB and the resistor's "bottom". Similar effect to 1); but both would be ideal.