I also think that the major risk points to all this is when elections or changes at the top happen, including the USA.
I hope the agreement lasts long enough for Iran to demonstrate that they have no other desire than to produce nuclear electricity.
I know both sides of the coin, and can see why Israel is slightly miffed right now. It's nothing short of a political minefield out there, and will be for years to come.
The dynamics of power will shift in Iran's favour now, and I hope it has a stabilising effect, but there's a brain cell or two that begs to differ at the moment.