Quantum Mechanics

Whenever I read through the theory of quantum mechanics I am reminded of a priest trying to explain the existence of God. They go through greats lengths to obfuscate and confuse, thinking to themselves that they if they can't be complete and thorough, at least they can make it sound like they are attempting to cover all possible weaknesses in their arguments. What I will try to do here is to first explain what problem quantum mechanics was developed to solve, and from this, what answers quantum mechanics provides that cannot be provided using another theory.

Questions that I would like answered:

1. Why is energy absorption quantified?
2. Why is electromagnetic energy quantified?
3. Why are there electron and nuclear orbitals rather than a random distribution of particles?