Haven’t had a samsung phone since the note 3, but I remember having issues with unlocking the bootloader, I think you had to use some 3rd party tool because samsung provided no guide in their manual. With nexus and pixel phones it’s really easy so them I can definately recommend.

Tesla chargers use CCS just like all others in the EU

I have actually never flown on a narrow body plane that had charging ports, so I wouldnt say “most flights”

https://purelymail.com/

I think it depends heavily on how much storage you’re allocating, if you allow uploading media that is. From what I’ve understood most of the bottlenecks are in DB operations so CPU and memory definately play a role.