You're welcome.
I agree with the KISS principle too. But in regards to the last item in the list I believe many are buying ScanGage II to provide transmission temp. This is directly related and should be watched when towing. Engine RPM, no. I think most tow vehicles have a tach so this is not necessary. And if you allow your transmission to do its thing, it should not be necessary even without a tach.
Dont understand "Brake Switch Voltage". That should be a constant of 12VDC unless Im missing something. The blue wire voltage and current should vary with adjustment and braking demands.