I would restrain myself

I would remove imagination and some intelligence from humans...

I wouldn't want to live in a created world/universe. I often wonder what life would be like if religious beliefs were real, though. I can imagine rushing your child to church to be healed of her brain tumor, or the pious and meek actually and inexplicably having better luck than the rest of us, or those who believe nothing religious or in the wrong religion falling victim to bad luck more often. Maybe even every living thing would have separate genetic codes, unrelated to each other, to make it clear that each thing was specially created and wouldn't even hint at family tree of life. Or maybe even those who believe correctly have special knowledge about reality that the rest of us don't have--if you believe in the right god, you are a perfect engineer, inventor, doctor, etc. I also see no reason for natural laws as such to exist, much less consistent patterns in reality discovered through scientific testing. The more and more you try to imagine all god claims and related claims to be true, the less and less it makes sense--but if it were true, it would still be true, and all the evidence around us would support it (as theists always claim). But it just doesn't.

There would be certain things that I would want to alter in people brains to start of with.