Regarding the planes, the Soviets had a plane working with hydrogen (and methane I believe). It's not particularly impossible, and at least much more doable than using batteries (for commercial jets).

The flying wing is a design improving the efficiency know for a long time (Airbus guys teaching us about it during my studies 15 years ago), but creates additional difficulties, on top of which the impossibility to evacuate the plane fast enough. You would have the same benefits whether your plane is using hydrogen or kerosene.

I still do not see planes using hydrogen. Just doing the math on how much electricity would be needed makes it really unlikely.