With regards to Valencia I think he might have been affected by RVP's arrival. Valencia has always been more quantity over quality, in that he's so effective because of the sheer number of crosses he'd get in. Even at his best he was never actually a particularly good crosser of the ball, as with most players with that much pace. He was devastating because almost all of our play went through him (often had no proper left winger either).
RVP, and Kagawa I suppose, has seen us play through the middle a lot more. So Valencia sees less of the ball, has less opportunity to put crosses in, and in that way I suppose it's almost a lack of quality in his game we're seeing now. He's not a player who'll regularly create something from nothing, he needs a constant supply of ball to be effective, and he doesn't have that to the same extent anymore.
On the subject of wingers and number 7s, christ I still love Ronaldo. I should hate Madrid after they knocked us out, and in that fashion, but I probably want them to win it more than anyone else left in the competition.