Not a single gram of uranium should leave Iran, and if it does, it should at least be sent to a UNSC permanent member like Russia or China with the power to influence global affairs.
Yes, 3 years seems to be very rational because Iran needs time to rebuild its nuclear infrastructure. Even 5 years is not that bad, but the US didn't accept even a 10-year pause. The best they offered was 20 years, per multiple news sources, assuming the newspapers write the truth.
Honestly, I think the toll system on the Strait of Hormuz is an overreach. Iran can do it as long as there's a war, but it will be nearly impossible to implement it in peace time.
Unfortunately, no guarantees can be made to ensure future US aggressions will not take place. The international law is completely ineffective against permanent UNSC members.
It depends on what happens in Lebanon. Lebanon will probably enter a period of civil war if they insist on disarming Hezbollah. The issue of Lebanon is very complicated and Hezbollah is under so much internal pressure too.