For (5), at least in most modern software companies, this isn't actually a "requirement," but places end up having some distribution of people from top schools

For (5), at least in most modern software companies, this isn't actually a "requirement," but places end up having some distribution of people from top schools anyway. This is usually just due to societal bias (oh, the guy from Harvard _must_ be good!), and honestly, on average, people who graduated from a top school (especially the ones that get in on merit and !legacy) are generally better than average.