Congratulations to Rosberg on a well deserved title. He did not put a foot wrong during these last races and did exactly what he had to do.
It's funny how Hamilton fans claim that Rosberg doesn't deserve the title because Hamilton has one race win more and qualified better, but suffered from reliability issues. I seem to remember that Hamilton's first title in 2008 came under those exact circumstances. Massa won 6 races to Hamilton's 5. Massa suffered an engine failure while in the lead in Hungary with 3 laps to go. Massa was the victim of his team messing up the pitstop in Singapore, sending him away with the fuel hose attached. And in the end Massa lost the title to Hamilton by 1 point.
Rosberg has had a very good season and all the complaints that he didn't beat Hamilton during these last 4 races are quite irrelevant. After Rosberg beat Hamilton in Japan, all he had to do was to stay out of trouble and finish 2nd and that is exactly what he has done. It's easy for Hamilton to beat his team mate when the team mate can afford to be beaten. In the first 17 races it was much harder for Hamilton to beat Rosberg. Besides, Hamilton did have fresher engines at the end.
Regarding the Mercedes team's messages to Hamilton, it is as simple as this: Mercedes has worked hard to get where they are and right now they have the fastest car. Both titles were in the bag and all they could add to that was race victories and possibly 1-2-finishes. Of course, the team wants to cash in these great results while they still can. After this race no one knows who will be fastest and Mercedes may not have the chance to win races for a long time. They would have looked very stupid if Vettel had been able to pass both Mercedes drivers and claim the race win, especially if next year Mercedes falls behind Ferrari and Red Bull and no longer can fight for race wins. And since Rosberg's third place was safe anyway, it would all have been for nothing for Hamilton as well.