I appreciate that you are simply expressing your thoughts, as I am. I know that the debate seems to have moved on to a discussion of natural evils(e.g. tsunamis, cancers) and I leave others to deal with this. My position, which I quite accept is different to yours, is that part of my moral framework is that, ideally, everyone should be responsible for their actions, and if there were a god who has moral standing, then that should also apply to him/her. As I see it, God is supposed to have created us. He was the one who decided to give us free will. He was the one who created the potential within us to do bad things as well as good things. Therefore He has ultimate responsibility for setting things up in this way. Unfortunately, in Christianity, it always seems that humanity gets the ultimate blame and God gets a free ride. The point about omnibenovolence is that Eden is supposed to have originally existed as a perfectly good place and that heaven, for those who make it there, is also a place of perfection. So, for me, the question remains, why did a so called omnibenovolent God see fit to make an imperfect earth and an imperfect set of humans in the first place, and why does He/She not take responsibility for His/Her actions?
Yes I would agree that such a God would have ultimate responsibility, even if that doesn't change my approach or religious beliefs.
If the scenario is that God gave humans the capacity to have a choice of responses rather than do as God wills - then God is ultimately responsible for giving humans the capacity for choice; and if we say that human choice is influenced by human desires and if God gave humans the capacity to have bad desires, God is responsible for giving them the capacity to have bad desires. In theory the moment they form the intent to choose something bad based on their desire, God could intervene to negate that desire but chooses not to, therefore God is ultimately responsible for the outcome of that bad desire.
The difference in our position is I think that unlike you, I am comfortable with the idea that the capacity for choice is necessary for spiritual development and therefore I don't turn away from religion despite the evidence that the capacity for choice leads to sometimes horrific individual negative outcomes from those choices. And I am comfortable with the idea that omnibenevolence relates to spiritually beneficial journeys rather than physically beneficial experiences. And I am comfortable or at least not repulsed by the idea that spiritual development could be a higher priority than physical well-being. Though as with most ideas, if the person who holds it has benign intent, then the outcome could potentially be tolerable or beneficial but if the person who holds it has bad intent then the idea could be used to inflict a lot of misery.
Presumably the idea of a Heaven is where people would not have those bad desires. Eden, on the other hand, if I understand the story correctly had a tree representing - not sure - bad desires? In Christianity I think they say it is a Tree of Knowledge - again presumably God created the tree so it all seems a metaphor that again makes God ultimately responsible. In the Quran it only says a tree of immortality. But the gist of the story is the same - I think the metaphor represents the idea that God gave an instruction, humans had the desire to not follow the instruction because God created both the capacity to have that desire to be disobedient and the capacity for choice, and so having followed their own desire they get kicked out of Eden to a place where they exercise choice and experience the positive and negative outcomes. And the story seems to be saying that the spiritual development humans have during their experiences while alive is judged by the entity with ultimate responsibility. You can certainly try to argue that you shouldn't be held accountable as you didn't choose to have any bad desires.
I don't take that as a literal interpretation where Eden and Heaven are actual places but other people may do. I am more interested in the ideas represented by the story - ideas about choice and consequences and justice. I like the idea of accountability, so I am not interested in arguing that I shouldn't be held accountable.