It's not - https://www.amazon.co.uk/dp/B00AFRXKFU
That's a question for the Linux dist, but probably not.
It's a protocol.
That's another client OS specific question, but very likely.
Look for TFTP router flashing videos on YT.
Yes.
It's referring to the flash.
It's supported by the brand new 24.10.1.
Walkthrough from an older thread, not it doesn't back up the current install pre flashing