Q8: Iran has been lying for years. What should make us believe them now? What has changed? They still support Hezbollah, threaten Israel, are promoting Assad etc.
It would be a mistake to believe Iranian policies and behavior are unchanging. The election of President Rouhani, and his connection to the Supreme Leader, represent an unprecedented change. The cabinet that Rouhani has appointed, including many educated in the US, is a clear signal of change.
A negotiated agreement will not require a leap of faith in Iranian honesty or good will. Iran will have to deliver on its end of a deal as the P5+1 deliver on their end. Everything to which Iran commits itself regarding its nuclear activities will be subject to enhanced monitoring and inspection.