1.) It is not just a deal between the USA and Iran but rather six nations (of which the USA is one) and Iran. The other nations have said they will go ahead and lift sanctions even if the US does not due to congressional action so the end of sanctions are a done deal
2.) Effectiveness? One more time according to Politifact "Under the deal, Iran will lose 97 percent of its stockpile of highly enriched uranium, the kind needed to make nuclear weapons. It will also give up 14,000 of its 20,000 centrifuges, the machines used to enrich uranium, and agree to only enrich uranium to a level unsuitable for weapons for 15 years. The deal also curbs Iranian production of plutonium, the other element that can be used to build a bomb. The deal bans plutonium reactors for 15 years and stipulates that Iran must dismantle its current one."
3.) Critics of the deal talk a lot about Iran having advance warning of inspections but what they don't tell you is the length of the deal which is 25 years. Hard to imagine them dodging inspectors for that length of time. Nantanz, the largest Iranian nuclear facility, will have security cameras installed that will be on around the clock
4.) Critics of the deal also like to complain about money being given to Iran but that money does not belong to the United States or Europe. Rather, it is Iranian assets frozen by the US and its allies,being held IMO illegally that is being released to its rightful owners.
5.) The best agreements between nations (and between people) are focused on one or a few items big picture, narrow focus yields the best results. Iran's relationship with Israel, funding of Hezbollah, its part in the conflict with ISIS should be subject of follow-up agreements (if at all). Completely unrelated to the Iranian nuclear program.
And of course still waiting for investigations on sanctions on Israel for its nuclear program.