About the X-1 being the first manned vehicle to break the sound barrier: there are records of Bf 109Fs surpassing 950km/h TAS in a dive when they tried to solve the issue of elevator and aileron lock-ups at very high speeds. I wouldn't call it far-fetched to assume that both G10 and K4 could surpass Mach 1 in a high-altitude dive without the wings shearing off. Alas, no proof. Just an interesting bit of aviation.

I think the X-1 is the first that could pass the speed of sound in normal level flight, without needing to dive to gain speed. That's my understanding at least. It ll depends how the record is stated though, it's almost certainly not the first manned craft to pass the sound barrier as you point out.

This got me intrigued with the few forward swept wing aircraft that I could think of (examples include X-29, Su-47).

I guess that the airflow being pushed in towards the fuse (opposite of the video) made designers hopeful they could capitalize on that and get extra maneuverability, but that generally didn't work out. Also requires extra strong wing material to account for flex, etc. Interesting.

God dammit, pressure is not how wings produce lift! (in his defence it's an extremely common mis-explanation)

If it was then they wouldn't ever work upside down (which they clearly can do when designed for it). Nor does the top and bottom airflow always meet again on the other side evenly, or in fact is the bottom stream always faster than the top.

Bernoulli's principle augments lift in efficient designs, but it's newtons 3rd law which actually makes them work.

You can even see the wash vortex falling down off the wings flying through smoke. It's the equal and opposite reaction from this deflection that causes the majority of lift and drag from a wing .