I'm glad you find God's love guides you; but I don't need someone else's love to make me a better person.
Becoming a good person is just a result of that though, not the goal itself. That's likely why a lot of atheists, myself in the past included, don't really get what's truly going on, because they all boil it down to a question whether being religious is about being a good person or not, often times in earthly terms, which sometimes leads to bigger messes. (Like the whole abortion debate, lobotomy, communism, and lots of other ways humans try to say "I know better".) While being good plays a huge role in the faith, it's not what it is ultimately about.
In either case whether the environment or the brain - or both - religion is not required to install it.
This too seems to be a common topic that is often misunderstood, which I still don't know to properly approach, but Christians don't disagree with that. The idea is that God has put certain inclinations into all of his human creation
regardless of whether or not they know of him. "The environment or the brain" is included in God's work. The matter is part of the creation. You didn't mention (nor seem to imply that?), but I just recalled that there's a common misconception that physical world is somehow detached from faith. It's a Gnostic, assorted pagan/traditional religion, occult, and so on view on the world, but definitely not a Christian one.
It’s a big question; but being religious won’t stop a person who has a defective brain from committing harm no matter the logic.
Not sure why, but David Wood comes to my mind, he's a Christian apologetic who's also a clinical sociopath.
Either way, that too isn't something uncommon or unexpected within the Christian worldview. Sin (which includes natural decay, diseases, and so on, not just things that are within our control) kind of works like that, and everyone falls short anyway even without serious brain damage.
Also I'd argue that you're unintentionally using a bit of vague language here (but that might be based on what type of atheist I was like in the past), "religious" is a vague word that doesn't always properly describe either Christians as a whole, or what some who call themselves Christian may or may not do, nor even maybe Christianity itself. For starters, religions differ. Some actually do push for harmful things. Second, I think it says a lot that Jesus had a massive beef with Pharisees. It was
religious people he was criticizing the most. These were people who were seen as good and righteous by, I'd say, worldly standards: by checking this list of things that one needs to achieve in order to be considered "good". Their hearts were rotten though.
I think a study in what and why humans even have morality is going to do anyone a good deal of good and is a worthwhile endeavor.
Yes and no. Ultimately it's going to be yet another attempt at learning how God's creation operates, or, if you're uncomfortable with this wording, how the world operates (on itself learning about it is good) which has a great chance of leading to a brief moment of false enlightenment, followed by drawing wrong conclusions and in next decades to be discarded as garbage data and everyone who was harmed along the way to be forgotten. Science on itself is a never ending process with a lot of things changing overtime, and social and psychological studies are arguably one of the most polluted fields with false findings, botched methods, and sometimes horrific outcomes. Like the "chemical imbalance" myth that is so prevalent nowadays, despite it being debunked decades ago, but that doesn't stop doctors from prescribing drugs to everyone and their mom the moment they get "unreasonably" sad. Or troon science. Or recent suspicion that two decades of research on Alzheimer's disease (which isn't even a nebulous psychological condition, but an actual physical, tangible disorder) were fabricated.
I'm not discouraging that, like I said, learning about the world is good on itself, and it may help both believers and unbelievers alike. But, uh... Going back to the initial point, that's not really the point of the faith at all.