The basic TWO Bind modes do confuse everyone.
When you do the regular bind with the sticks neutral, gear down etc the reciever will send all controls to those positions ONLY on startup. This is helpful when you turn the rx on first so that flaps will stay up and gear down (the positions they were in when bound)

But the second NORMAL failsafe, which happens when the model has connected to the TX such as in flight and then loses signal will only send the throttle servo to idle, all other controls will stay in the last commanded position until control is regained.

The THIRD bind mode is not covered in the DX7 manual but is covered in the X9303. That is where you remove the bind plug after the lights are flashing (which leaves them flashing) and then turns the TX on in bind mode but with the sticks and switches held in the positions that you want them to go to in case of loss of signal during flight. On DX7 (and surprise DX6i) with quick connect this will preprogram a failsafe mode. Some competitions require controls to go to "crash" positions should the radio lose signal, this accomplishes that function.

Just go try these things to learn for yourself, there is no harm done to anything and you will quickly understand what all the bind modes can do for you. But when finished go back and set the specific bind mode you want for your model, its fun and it is simple.