You're foolish and naive to think the sanctions will get booted out with an agreement. The Americans still have some of the sanctions they placed on Russia from back in the Soviet Union times. Iran WILL NEVER be sanction free until the mullahs are gone. That's simply a fact. Sure, there will be easing of sanctions, but complete removal is an uneducated man's dream, nothing more.
And why wouldn't they want Iran to boom? The global economy isn't a pie where things get divided. It's a pie where everybody fights for a piece, but the pie has been getting bigger every decade. The bigger the economy in X nation, the more opportunities exist for banks and corporations in Y nation to take advantage of. It's also a fact that the more countries trade with each other, the less of a chance for future conflict and war. In the US, large banks and corporations have A LOT of voice. They lobby the US government and get what they want. They don't care about human rights or Israel/Palestine. They care about their bottom line. Contrary to what you say, they want a sanction free Iran.
That said, unless the mullahs pack their zambils and move to saudi, Iran will not be sanction free. An initial agreement will only ease sanctions and limit them. Life will marginally improve, but there will not be any drastic change.