SSD, you again show a lack of understanding. The unstart problem was not the result of "unsophisticated intake design" as you put it. The intake design was incredibly sophisticated, the problem was the state of the art at the time in controlling the intake parameters. This problem was later solved with the invention and adoption of digital computers to manage the parameters.
the need for exotic fuels
So what fuel do you suggest could have withstood the operating environment? Wood or coal perhaps?
(inability to get through 'the sound barrier' in level flight
Wrong. The dive procedure was to get through the exceptionally high drag of the flight envelope in the most expeditious manner. Expeditious in this context is as quickly as possible and with the lowest fuel burn.
The accident rate is indicative of an aircraft that is operating at the very margins, mechanically, aerodynamically, technologically. That's why not everybody got handed the keys.
You best do some reading.