Iran deal... what's at stake?

I have to say that I'm more than  little puzzled at the strong reactions against the proposed deal with Iran.  It significantly attenuates Iran's ability to produce a nuclear weapon.  It opens the doors for inspections wider than they have ever been.  It strengthens the pro-western factions in their government.  It offers relief to the crushing burden of sanctions, borne largely by the least able.It strengthens the strongest enemy of the radical Sunni groups like ISIS. 

What are the arguments for the downsides?  It does allow for an infusion of cash to Iran and will cause a shift in power in the region, but that looks to happen regardless of whether the agreement is embraced by the US.  It has been argued that more sanctions might get us a better deal... but the European community has said that they will not observe sanctions any longer so this will happen regardless of what the US does.   Iran is not trustworthy.  Again, nothing changes there.  At least with the agreement there are inspections.  In addition, it calls for the dismantling of a significant percentage of their centrifuges which would push out the time frame needed to procure enough material to make a bomb from as little as 2 months (currently) to a year or more.  Finally, if Iran broke the agreement, that would catalyze the world community against them. 

Significant leaders in Israel are frightened by the agreement but other significant leaders have spoken in favor.  An important observation here is that Iran, while not being trustworthy has also shown itself to not be crazy.  In spite of rhetoric to the contrary, they have not taken steps that would threaten their future as a nation.  Israel on the other hand is crazy.  They have shown repeatedly that they will do whatever is necessary to defend themselves and that they would not hesitate to use matching force and more.  If Iran was to produce a nuclear weapon and use it against Israel, it is abundantly clear that Israel would respond with their significantly larger nuclear array and Iran would be completely annihilated.  Without the continued focus of the world on Iran's capacity to build nuclear weapons, it is precisely the Israel capacities that push them to develop these weapons.  Many military leaders in Israel believe that this deal does indeed serve to make Israel more secure, not less, and will serve to stop Iran's program to develop these weapons.

So short of diplomacy, what is the option another than another war costing trillions of dollars and 100's of thousands of lives?  We have seen the long term results of wars in the Middle East and they are not positive.  Given the strong points of the deal vs. the single option of war, why would anyone argue against it?

The cynic in me sees only one reason - oil.  If sanctions are lifted and there is no war, Iran will likely flood the world market with oil, driving down the cost - they need the money.  Fracking and enhanced drilling techniques will become too expensive to be practical and profits will drop significantly for the oil companies.  From what I can see, the only ones who benefit from this agreement failing are the oil companies and the end result is once again seeing young men and women dying to preserve the profits of multinationals.