Woah, that was a long read.
I agree with Sakae - Ferrari is a famous enough brand that most drivers want a race seat there. Unless they have dropped into the midfield by 2017, I dare say Sebastian will find his way there.
And it is also an interesting point that Ferrari has stagnated in its development recently. I think the loss of Schumacher in 2006 hit Ferrari's development the hardest, but from 2007-2008 Kimi and Massa seemed to be holding on quite well. It was only after 2009 that they seemed to be unable to develop a front racing car. Now I am probably giving too much credit to Sebastian, but I think when he moves to Ferrari, the development should pick right up again. After all, isn't he famous for staying with the mechanics and studying all the technical aspects of the car? Sure, Ferrari may not have Newey's genius, but they never needed it before. I think with the right feedback (and maybe a few tricks from Red Bull that the driver picked up) they could be a real force from 2017 onwards. If that is the case, Sebastian domination may be a frightening prospect (to some) indeed.
Of course there are those that believe drivers do nothing but just drive the car on track (and the speed is all due to the car and not the driver). In that case, then Red Bull will be onto 10 plus WCCs soon.