The analogy between Conclusion 2 and the Born rule is precise: sampling from |ψ|2 multiple times does not create multiple distinct particles—it merely traces out descriptions of the same underlying ψ. The particle is the equivalence class, while the samples are its representatives.
Correspondingly, running a DNA simulation multiple times does not create multiple instances of Alice; rather, it traces out different representations of the same ”Alice” equivalence class. Computers do not create new information.
Axiom 3 does not restrict to classical computation. The computability claim covers any physically realisable process, including quantum processes. Quantum computation is an alternative physical realisation of the same formal state-transition structure and is therefore covered by the axiom without requiring a separate argument. Substrate independence follows for quantum computers by the same derivation as for classical ones.