I follow Iranian politics very closely. The hardliners have already sabotaged the deal by undermining Rouhani in every instance. And the USA is sabotaging it by making it hard for Iranian-Americans to send remittances back home because private banks still consider Iran to be a huge liability. Land of the Free.
The nice Iranian girl can live and study in Germany since you're accepting everyone in. You have good schools, don't you? Let us be the superpower. She's not entitled to an American pedigree if her government is acting shitty.
Iran is not a stable country. They have ethnonationalist movements from Azeris and Baluchis and they have a discontented population. Most importantly, they, the government, harms US interests and wants to wipe our best buddy Israel off the map.
If we didn't put pressure on the Supreme Leader, he would control half of Iraq, the Gulf of Aden (through Houthi proxies), and a very large amount of the world's oil trade. Iran exports 90% of its oil from one port, so they have to keep expanding to survive. Pretty iffy if that country is a declared enemy of the US. They also killed 3,000 US soldiers in the 80's through Hezbollah. We don't want to help them so much, honestly.