Well, the system is still the ACA signed by Obama. The effort to repeal to Obamacare was unsuccessful.
They were not given "250 billion." The US paid Iran roughly 1.5 billion which was essentially a refund. Before 1979, Iran had paid hundreds of millions for military equipment that was never delivered. The payment was a refund + interest for nearly 40 years.
You're so far off on the terms of the Iran deal. It did not give them permission to build a bomb in 10 years and inspectors were allowed access to ANY site in the country, not just declared military sites, within 24 hours. Maybe try reading up on it first?
No one is saying that Iran is not dangerous, but the repeal of the deal was only sought by lunatics like Netanyahu or neocons like John Bolton who want nothing more than a forever war with Iran.
Pulling out of the Iran deal, also probably helped doom any potential deal with Kim Jong Il. The logical conclusion for the North Koreans to draw was that the US won't necessarily honor its commitments. Why should they make a deal when the rug could be pulled out even if they're complying?