Why does the paper backup stay the same even if I add new addresses to a wallet?

[pf]

I can only assume Armory pregenerates a lot of addresses at wallet creation. So that begs the question, how many addresses? At which point, after adding how many addresses, will the paper backup need to be printed again?

[Carlton Banks]

Armory wallets use a seed to create new addresses, it's computed using the part of the paper backup that's headed "Chaincode". All the addresses that the private key can spend from can be generated using that chaincode.

This all happens seamlessly, courtesy of the code. No need to use the chaincode yourself for any reason other than to record or restore a wallet to/from paper.

[pf]

Armory wallets use a seed to create new addresses, it's computed using the part of the paper backup that's headed "Chaincode". All the addresses that the private key can spend from can be generated using that chaincode.

This all happens seamlessly, courtesy of the code. No need to use the chaincode yourself for any reason other than to record or restore a wallet to/from paper.

How well have all these specialized Armory manipulations be audited? I assume they haven't been audited and scrutinized as well as Bitcoin Core has. Forgive me, but I'm a bit paranoid. Not sure if I can fully trust Armory :S

[Carlton Banks]

How well have all these specialized Armory manipulations be audited? I assume they haven't been audited and scrutinized as well as Bitcoin Core has. Forgive me, but I'm a bit paranoid. Not sure if I can fully trust Armory :S

Don't know. Unaware of any code review external to Armory Technologies Inc., all I can tell you is that address determinism has likely been well used, and this is since 2011 I believe. They've used the same wallet spec since very close to the beginning, so it's at least mature, if not professionally & independently reviewed. I can attest that it's never been a problem for me, and I've used several hundred addresses from a single wallet without problems.