I think you are pushing him too far, if you are asking him to keep wickets again.He was good enough to accept the role, since the situation demanded it.Now, i think the goal should be to find a suitable wicket keeper/ batsman to fill the slot. Also, Rahul can concentrate on his batting which is his natural.
He should be keeping the wicket's in one day games as we get an option to allow extra batsmen or bowler in the side. He should take a lesson from a man like alec stewart who served his side for so many years.
Rahul is a great guy and a great cricketer. But, India needs him to keep wickets as we do not have a good enough wicket-keeper batsman. Besides, we can then play an additional batsman or bowler or allrounder. My team in batting order for the Tests-- Laxman, Sehwag, Dravid, Tendulkar, Gangully, Yuvraj, Karthik, Agarkar, Harbhajan, Kumble and Zaheer with Kaif as 12th man.