I think that your analysis is brilliant (as always) and I agree with you about Dozier. But I have different thoughts about Hendricks and Plouffe.
Maybe they sent Hendricks down to help him gain some confidence? Or to give Diamond a chance while he is hot? It seems to me that Hendricks has good stuff, but he is too tense when he pitches, especially when he gets in trouble. A few games at Rochester might help.
As for Plouffe, he does not seem to be focused. I was at an Angels game last year and Plouffe was playing second base. The Angels had a man on first and two outs. Plouffe fielded a sharp ground ball and causally trotted to second, forgetting that there was only one out. If Plouffe had been paying attention, it would have been an easy double play. The Angels fans had a field day mocking him after that and it seemed to me that was not focused at the plate.
Plouffe has had stretches where it seems clear that he has great tools in the field and at the plate. I think that he has the talent necessary to be a good player. But, like Valencia, it seems to me that Plouffe would need to get his head (and heart) more into the game. It also seems to me that the manager should do whatever he can to help this type of player get more focused. I don't know if any manager could "fix" Plouffe or Valencia, but it seems to me that they both have a lot more talent than they have shown this year.