Oh, i see, I thought you did believe in something like it because you talked about buddhism. Sorry, my mistake.
What I don't understand then is that you said: "God would surely still be bound by certain rules, even if those are of his/her own creation. You can't pull matter out of nothing without creating anti-matter. You can't create light without creating darkness. Each thing creates its opposite and that goes for health and sickness, good and evil, joy and pain, etc." I don't understand how you can reconciliate that with the idea of heaven at all, because the idea is precisely that there is no sickness, evil or pain in heaven. And if there's no reincarnation in your model, then people would either go as they are more or less now to heaven (which would basically make heaven Earth 2.0), or they would be changed somehow to achieve real peace, and if so then God surely can create a world with different rules where there's no suffering, which is the opposite to your premise.
And to clarify, the traditional understanding of the subject seems to me to be that God certainly could create a better world in terms of less suffering (in Genesis, death only comes as a punishment from God) and perfectly happy individuals (say, angels). He just doesn't want to, because he wants to create a type of good which necesitates the experience of suffering (but it's not a ying-yang type of thing, but rather temporary step) towards absolute, universal good. So in a very real sense, the classic view is that suffering comes from God (Job is a good example of that). That's what I'm trying to defend. Your view that "the system runs itself now, without intervention from a higher power. Probably there's no decision that children starve - that is determined by weather patterns, human history and many other factors" seems to suggest that God didn't foresee, planned and approved the reality of the world. Which to me sounds like saying that the world is arbitrary, that the particular development and events of history don't matter because God only cared about the initial rules of the world.