As chuck noted the Young handle does not have end point adjustments on the throttle trigger or any of the other channels.
I have been using the Bill Young handle quite successfully now for I beleve about 12 years however this has been only with glow aircraft and as noted by Chuck I beleve your problem is related to this lack of endpoints when using a ESC.
I am not sure how to help your situation as I am not a electronics type. Trouble with this is the Young handle was developed some years before the whole world except me it seems was in such a mad rush to convert from glow to electric. Your handle I suspect would work fine if you left out the Rx and just used a servo but of course that is a problem for the ESV.
Using the Young handle I found that you had to be creative with the actuator horns on both the servo and throttle arm to acheve reasonable endpoints for even the glow installations, kinda like the not so good, 'good old days'.
Now after those years of successes with the over the wire systems which I am still using today with two airplanes set up for it. Also note with all my controlline airplanes I have to have thottled systems because I fly from a wheelchair. I am going to abandon the over the wire systems altogether and this is only possible because of the miracle of 2.4 over the air systems.
The real trouble with an over the wire system is it requires four connections or (Y)'s to the flying wires two at the handle and two at near the leadouts. These are the Achilles Heal and over those years these take a beating and I have suffered every possible mannor failure usually related to this Achilles Heal and had to complete flights with no throttle which for me is a genuine problem.
My next airplane will us a a simple over the air system which will consist of an old Hitec Prism 7X with the Hitec 2.4 module system and of course a RX and small battery as well as a small servo on board for the throlle. You could of course just use the ESC plugged to the throttle plugged to the throttle channel in the normal way and of course just as with RC you will have full end point control. My intent is to also use an onboard servo an release for a launch stooge as this will greatly facilitate my set up time when I am alone and minimise trudging through the dirt in my wheelchair.
Monellar I suspect your problem when you tryed using RC with a separate operator for the transmitter, if I read right was at the root of your crash. You need to control everything and not depend on a second party.
The system I will use next will be a conventional over the air and the transmitter will be worn simply from a neck strap and (key point) backwards with the sticks pointing toward the airplane, the ordinary attachment point for the strap cannot be used to do this. Now I have tested the ergonomics of this setup by hanging and operating the sticks like this as a test and I was actually flying the airplane with my Young system. The neck strap will need to be attached in some fashion to both sides of the transmitter.
What I have found is that its very easy to operate the throttle simply with your free hand or any of the other sticks for matter. The transmitter is worn high right over you chest and not low near you beltline. Its actually easier to do this than to train yourself to operate a handle for elevator control and a pistol trigger for throttle. That was a definate skill set that had to be learned with an over the wire system using a trigger operated throttle.
Oh by the way Monellar wecome to RCU
John