1) Quantum Computation: What exactly are the abstract models of computation here? Are the Classical Computation models i.e. https://en.wikipedia.org/wiki/Model_of_computation applicable? What other new models have been invented?

2) Quantum Computers: What is the Physics, Organization and Architecture of these? In classical computers you have semiconductor physics, electronic elements and voltage thresholds mapping to logical 1's and 0's. This is then used to build layers of abstractions. What are their equivalents in a quantum computer? https://en.wikipedia.org/wiki/Quantum_computing has a lot of info. but not quite structured for understanding.

3) Quantum Programming: A lot is mentioned at https://en.wikipedia.org/wiki/Quantum_programming and Amazon lists a bunch of books on this topic but am not quite clear on how everything fits. Also as i understand, quantum computing/programming can be simulated on classical hardware but am not clear on the how.

PS: Some detailed examples as to how quantum computers/programming actually help you solve problems which cannot be solved on classical computers would be helpful to bring everything together. Shor's algorithm (https://en.wikipedia.org/wiki/Shor%27s_algorithm) is often mentioned but perhaps starting with a far simpler example would be more accessible.

PPS: In particular; I would love to hear from folks who actually study/research/work in this domain regarding what they actually do, its real-world applicabilities and how to go about learning the subject.