
dont know about the back brakes bud, esp if it rolls ok!
im sure there is summin you can do to the MAF, like disconnect it for a while and see if the revs dip, i saw it on this forum somewhere...cant remember where sorry.
the symptoms sound just like when my MAF went thats why i suggested it, my first one went @ 41000 miles.
very easy to take off, its 2 or 3 screws...the MAF is located between the air box and the engine... it has a plug comming out of it (disconnect this) and when removed it looks like a sieve/grater.
on that website they are 70ish quid but i dont know how much p+p would be...
as for the limp mode, it could be i guess, but you would prob need vagcom to diagnose that

otherwise you could wait on here for others to post...sorry i cant be of much help m8, i know how frustrating it can be.