Good Morning.. Do a search or look around the forum and you should have your answers, but..
(1) MR>Avios is available via amex.com, very optimal.
(2) Instant
(3) No one knows when the next promo would be
(4) Cannot be traded back, ones transferred thats it.
Now any more questions please search. This is my one good deed per day, and I can now be mean the rest of the day..