Nice list Dolph, but I'd put Rafa at 3 on grass, Nole at 4 and Tsonga at 5. And Nadal at 5 on fast hards.
Debatable between Murray and Novak on fast courts as well.
Anything regarding Nadal is really hard to gauge at the moment (except on clay) because of his long lay-off. for example the way Murray is playing now; would Nadal beat him on slow-hard or grass etc. I gave Nadal some provosional rankings
As for the Murray, Djoko thing; Murray possibly has the better game than Djoko, but between the ears Novak is superior and thats what makes him a slightly better player than Murray overall IMO.