I don't know why anyone bothers adding captions like "That's the truth" when talking about future events. I can only presume you want not to be taken seriously.
As for Nadal and grass, he lost to Müller and Rosol in R2, he would have lost to Youzhny in R4 2007 but for the Russian injuring himself halfway through, he was in severe difficulties against Kendrick in R2 2006, Haase R2 and Petszchner R3 in 2010. Sure, Federer has also had troubles against Falla and Benneteau, but those are the only two five-setters before the QF for him since he beat Sampras in 2001. So it's obvious which of the two is best week one. In week two, the difference becomes much smaller.
I agree with this. It came two and a half years after his previous win. It feels like his swansong to me, same as Sampras' last US Open. Of course, Federer is still in the top four, and still consistently making the second week of majors (unlike Sampras). But still...
Roger needs things to go his way. Let's imagine he had Ferrer in his half and murray and djokovic battled it out in the semis in this year's AO. Certainly Roger would have made the finals and would have a shot. Unfortunately he ended up with murray in his half.
Yes, he is more vulnerable now to fall in the quarters but if he has a decent draw, for example, Ferrer in his half in Wimbledon (if Ferrer is still #4) and nadal in the other half he will have a shot at the final and in the finals anything can happen.
I say Roger has 2 more slams in him, 1 Wimbledon and 1 US Open.