I don't see the transmitter being within reach as a problem. I have the starter firmly secured to the ground (I use a couple of cheap long screw drivers driven into the ground through a couple of holes in the starter to achieve this, works well) I have a 'u' shaped plane holder thing again securely screwed into the ground via a piece of coiled steel(came from a picnic dog restraint I found in the hardware store.) I secure the plane restraint about 500mm plus the length of the plane behind the starter. I place the transmitter on the ground by the tail of the plane. I am easily able to push the plane into the starter holding the plane around the main wing. If I need to adjust the throttle the transmitter is right by my hand. When the engine starts it is simple matter to move the plane back and put the planes tail plane into the plane holder, the transmitter is then about the wing area of the the plane and can easily and safely be picked up to adjust or check the operating engine. A friend made me a plastic cradle for the transmitter to sit in so it doesn't lie on the ground, but this is not necessary.
I agree electrics also need care, once the battery is connected , knock the throttle on the transmitter and the motor starts. Also electric motors won't stall if they hit something (including YOU) but will just keep on chewing. I am not aware of any light weight switches that will handle 20, or 30 or 40 amps which electric motors will draw, so a switch is not an option. However I am thinking of an automotive fuse (available in high amperage sizes) that you can insert into a fuse holder on the side of the plane when you are ready to fly. However I don't know if a suitable fuse holder is available, and this system is putting another area of potential weakness and failure into the radio and motor systems of the plane. Is this solving one problem and making another problem?
I found this link, this item is along the lines of what I was thinking of and was trying to describe.
http://www.atlantahobby.com/shopexd.asp?id=6606
Props are dangerous and fingers and hands must be kept well away.
Cheers
David