If Federer hit every ball to Nadal's backhand, it would not work unless every ball Federer hit was a bullet. Nadal can make backhands into forehands if the ball is not a bullet. Additionally, all Nadal has to do is hit to Federer's backhand and then the next ball Nadal receives will not be a bullet, unless Federer is willing to go for broke with a backhand. Federer can go for broke with a backhand, but not all of them, or the errors will flow. Also, Federer would have to completely give up on hitting backhand slice, because Nadal can run around them and hit forehands.
Pretty much spot on. Except he still needs to throw in the occasional slice, either if on the extreme defensive, or a deep offensive slice, just to keep Mr. Nadal off-balance.
As I've said elsewhere, the real problem for Mr. Federer against Mr. Nadal is that when the court/balls are playing slowly (such as was the case in the semifinal at night in the cooler weather), he has to play very high risk tennis, flattening out his shots to make consistent winners without a slew of unforced errors, and no one, not even someone with his talent can keep that up succssfully for very long. Notice that when he had new balls to work with for the first 3 games or so, he was able to hit his penetrating shots with a bit more spin for winners and have easier service games. But after 4 games or so, that simply didn't work. Mr. Nadal was able to retrieve balls that would normally be winners, and make Mr. Federer hit more shots. Mr Federer then had to start flattening his shots so much that his margin of error decreased substantially, and with the higher risk, he was frequently hitting the top of the net. He tried other strategies, but these were also low percentage plays against Mr. Nadal, such as drop shots, which are risky, and serve and volley which are difficult to carry out successfully when its playing slower, especially against Mr. Nadal with his passing skills. And the more he made those errors, put even more pressure on him. I think in slow conditions, one's only chance against Mr. Nadal is to simply stay out there, be patient, rally back and forth in the middle of the court so as not to give too many angles, and not try to hit winners as much until there is a clear opening, such as a short ball. But this requires a lot of patience, and is not how Mr. Federer prefers to play the game.
Even with conditions against him, Mr. Federer did well to win a set, and kept the score close in 2 out of the other 3 sets. Once the conditions were evident, I expected worse.
I believe he would have had a much better chance against Mr. Nadal during the heat of the day when the balls were clearly sailing through the court faster. This is probably why he requested day matches, esp. with Del Potro. Unfortunately for Mr. Federer, semifinals are only played at night at the AO, so he was behind the proverbial eight ball against someone with the retrieving capabilities of Mr. Nadal. When conditions favor Mr. Federer (i.e. fast court/low bouncing balls), he can make Mr. Nadal look like a fish out of water. But with the move toward surface homogenization we don't see those conditions as much any more. And where we see them, Mr. Nadal is less likely to go deep enough to meet Mr. Federer, except at the WTF, where it is round robin.