Also, I’ve figured out how people take left turns here

It’s not random at all, in fact there is a norm so strong I would almost call it a rule. If the person in the oncoming lane can reasonably be expected to have enough time to stop or swerve before crashing into you, it is safe to take a left turn in front of them. So once again, 亂中有序 luanzhong you xu: in chaos, there is order.