they require that God's commandments do not already require of us? When we do these things, our culpability may increase, but the things God expects of us do not change. Why is BYU different? Why does BYU ask more than God when we make sacred covenants?

That leads into the more glaring problem with your comparison. All of your examples (except becoming an apostle) are commandments that, from an eternal standpoint, God requires of all of us, is best for all of us, and that is open to all of us. BYU is none of these things. Similarly, going to BYU is not a "blessing," at least not the way God operates and not in the way you appear to be using the phrase (any opportunity for higher education is a blessing in a general sense). God does not limit the blessings for gospel covenants; they are available to everyone. To put "blessings" for attending BYU on that same or similar level is ridiculous and completely antithetical to the gospel because of the limited availability of such purported blessings. It is also offensive and creates a perception that is contrary to the church's (and BYU's) purpose.

BYU is a great school that does a lot of good and is a great educational opportunity for many people. It's just not in the same universe as sacred saving ordinances.