Regarding the Mercedes team-order, there's a very good article/interview in Auto Motor und Sport (AMuS) where Ross Brawn explains the reasons behind not letting Rosberg passed Hamilton:
http://www.auto-motor-und-sport.de/...-beide-fahrer-mit-spritproblemen-6802387.html
Link is in German, so I'll just translate the important points:
- At the post race interviews, Hamilton, Rosberg, Wolff and Lauda did not know the full extend of the fuel-saving situation
- The cars need to be fueled 2 hours before the race starts, at which they calculated worse track conditions
- "Overfueling" would have ment overal slower lap times because of the added weight and strain on tyres.
- The race was a lot harder and quicker than anticipated, hence why they used more fuel
- To reduce the impact of the underfuel, Nico and Hamilton only did 3 warm-up laps before parking their cars on the grid for start preperation
- When Rosberg and Hamilton had caught up to each other, they had both received the "lift and coast" command to save fuel
- Rosberg was using less fuel because he was driving in Lewis' slipstream and DRS
- Brawn stopped the battle on lap 44
- Brawn states that both drivers had received orders to save fuel at least 10 laps earlier
- If they had continued to battle against each other, both drivers would have been unable to complete the race
- If Rosberg had passed Lewis, Lewis would have been at the advantage of using less fuel because he would have been following Rosbergs slipstream
- Leading driver gets strategy advantage.
- Nico wouldn't have been able to persuit the Redbull because he would have run out of fuel.
Brawn also explains in the article that the first thing they do when running low on fuel is to give the order "lift and coast" to the driver. It's up to him to adapt and lift earlier before corners to save fuel. Only if things get really crucial, they use engine settings to reduce the amount of fuel their using.