We can absolutely get that working! Did you test the first example in the first post? That example should turn on the onboard LED at pin 13 when the channel goes below 1300 us. You can change that to 1500 for a standard center value or change < to > if the throttle channel is reversed. You can also use the serial monitor with that example to read out what the program registers as the channel value at any time to find your specific center.
If that does what you want, that's great. If you want it to also understand the difference between braking and reverse we need to complicate things. If this is not what you were asking for, let me know