How can you get a flight up grade from economy to business class?

The main difference is in the level of service and comfort. Obviously the fare is higher in the executive class because of seat pitch, seat recline, inflight service including meal, entertainement...

You can. But to be professional, I wouldnt.

88%

Well if they are in your class don't sit near them and if you have any other friends in the class sit with them or you can confront them

Fly Emirates