Good job on the write up!
One note on the power resistors...
These are required so that the BCM does not sense that the bulb is burned out. Without them, the car will display an error as well as blink quickly.
The heat sink for these resistors are not needed. That is because almost no current is going through these when the blinker is off. When the blinker is illuminated, current does flow through. Since the blinkers are on and off, and usually only for a short duration, these resistors will rarely even become warm. My suggestion is to hide them however you can.
Any additional details on how you got the middle wire to stay contacted with the bulb wire inside the connector?