Short Answer: No.
Long Answer: To be eligible for RAF - you need to
create an account by clicking the invite link. This obviously will be a different account from the one you have your monk on (Regardless of whether its a Cataclysm account or a full blown trial account).
I am not sure what the rules are regarding character transfer between accounts - but the last I heard (you will need to check this out before you decide anything) as long as the WoW accounts are linked to the same Battle.net account, you are allowed to xfer characters from one to the other. This will involve an additional payment to Blizzard even if it is an option for you so bear that in mind as well.
Would recommend that you not use the insta-level option at all... its fine for a returning player who wants to roll a new toon for example - but if you are totally new, I pretty much guarantee that a level 80 will be way too complicated to handle, your mileage will vary depending on class/spec of course - but even the simplest classes are not all that simple by the time you are 80.
PLUS - you are cheating yourself of a lot of content/quests/playtime. Contrary to what a lot of people think, WoW is not
just about the game at level cap. Believe me, if you are willing to go into the world and quest instead of just chaining instances - the game can be extremely enjoyable while levelling up without the stress of dealing with the nutcase wannabe hardcore types floating around at level cap.
TL
R - pace yourself and enjoy the game for everything it offers - there is more to it than level 90 raid/challenge mode/arena/rbg