Well I finished it up, and finally got the RC values from the transmitter and receiver synced up. Had to make the LSB an unsigned char before I could do math on it, I kept getting weird results. Now everything works great and I did a little test flight this afternoon. The codebender links for receiver and transmitter sketches are on the right, most of the instructions are within the comments of each sketch. Controlling my quadcopter is pretty sensitive, especially the throttle (Left trigger), but this can be easily alleviated by setting an exponential curve on your particular flight controller. There's plenty of room on the transmitter to add some preprocessing to the RC signals. A rolling average to slow the response might help a little, you could add dead zones and do plenty of other neat stuff. I set up the A button to toggle AUX1 (arms my quad) between 1000 and 2000, you could easily set up an other button to do the same for any other auxiliary channel.
I wonder if there is a way you could make it use the sum of both triggers for throttle position. So just one all the way in would be 50%, both halfway would also be 50%. This would give you much finer control but still allow for great punchouts. For FPV flying you would be able to just keep one all the way in and feather the other one as needed.