How do I prevent the player from dying when they fall in the void?
The only way to do it is to lift it up the Y-Axis. I recommend selecting everything then moving it up an EXACT amount of studs (e.g. 100) Then just change the script and add 100 studs to all the values. To be safe I would increase it by a lot more studs than you think you will need.
This is the only way I know of and I think is possible.