Is he saying he will get to 500mph in the space of 1 mile? If so, what is the resultant g-force for that acceleration?
Nothing too substantial. I seem to recall top fuel dragsters do the 1/4 mile in about 4 seconds. Even going from 0-500 MPH in 4 seconds it's 5.7 gs, well less than what Red Bull air racers see. And realistically it'll be more than 4 seconds, probably more like 8-9, which would bring it down in the range of <3 gs. That, however, assumes linear acceleration, which this probably won't have.
At the height he is planning to get to he could just buy a drone with a camera. Or a balloon. Or take a flight on an airplane. But yea, Darwin.