Today, in the current political system, the best candidates for those positions don’t want to serve because the gridlock prevents them from getting anything done.  Also, today the hassle of spending more than half their time campaigning, raising money and enduring the mudslinging is a poor use of their time.  With the new system they can just walk into the job and will be motivated to seek the positions because they can be so productive for the American people and can make so much money.

The states determine that, like they currently do to establish other laws related to choosing politicians.  If they want more participation by the public, every four years, republicans and democrats could post on a website their proposed plan and a survey could be taken to determine the winning group for the next four years.  

Everything is determined by the writers of the amendment but preferably it would be left up to the best judgement of the Government Accountability Office (GAO) which is fiercely independent of Congress.

You won’t and that’s one of the best features of this system that will pull everyone together instead of tearing people apart.  Their job is to make decisions that maximize the benefit to everyone affected by those decisions.  They first try to give everyone what they want, which reminds them to figure out what everyone wants.   That helps them to find the best solutions where the least number of people don’t get exactly what they want.  If the maximizing decision is unjust to someone they can be compensated in some other way.  For example, if someone doesn’t get exactly what they want on one issue, they should on the next.  However, if someone has a legal right to something they get it.