RotS, etc.

I wouldn't call myself a Star Wars expert, but I think I have a pretty good grasp as to what is going on. that being said, I am thoroughly confused on a number of issues and perhaps some of you can enlighten me.
First, who is Sifo-Dyas? Was it really he that initiated the cloning or was it someone else (Dooku?) acting under his persona? Second, and Slaps and I have discussed this a little, what happened to R2 between RotS and ANH? Some sort of robo-arthritus? I mean, he was doing Jedi leaps in RotS and I would have thought that a number of his special abilities (flying, lighting droids on fire, etc.) would have been handy in later films. I attribute this to Lucas' inability to create any sort of reasonable consisitency between the original films and the prequels. Third, and most importantly in my book, why do we not get to see the Yoda planet with all sorts of Yodas running around?
I did think that that RotS was by far the best of the prequels, not that that is much of an accomplishment. I would not compare any part of it to LotR. In fact I would probably say that Peter Jackson took slightly progressive steps towards Lucasdom with his gradual increase in liberties he took with each progressive film in abandoning the true storyline, both in events and overall tone of the films vs. the books. I am not trying to draw any sort of comparison between LotR and Star Wars prequels as I don't think that it can be reasonably done, but responding to Pallando's comment about RotS achieving LotR quality at some points, which I don't think it does.
Finally, someone needs to explain to me why this isn't funny: http://sportsillustrated.cnn.com/2005/football/nfl/06/01/bc.fbn.49erstrainingvid.ap/index.html