everything has to have an origin, except God?
The actual argument is everything has to have an origin inside the universe, thus our universe to exist must have a cause exterior to it. We call this cause God. It's not a question of higher being, just that a universe where the effect predates the cause can't hold. God is not less omnipotent because they can't make a round square.
Why couldn't an all-powerful being have chosen to create the universe such that everything is good?
I thought I answered this question twice, I'm sorry if I'm not clear, English is hard for me. So I'll try again: because it's logically impossible to have a universe which is not a part of God, thus independant and free, that is also perfectly good, as God is perfectly good. Put as a formula, the formulas
universe = good and universe ≠ God are not possible at the same time if God = good
Mind reading