I wish to reply further (also to cellards last post above); for now, simply to address one issue:
Regarding address formats. I'm seeing a lot of engineering-level discussion but better would be to simply toss samples at test groups and have them type them in, gather comments and so forth.
They
did. Did you read what gmaxwell said upthread? Red highlights are here added.
Bech32 is designed for human use and basically nothing else [...]
In actual testing transfering bech32 addresses to another person is on the order of 5x faster with bech32 due to errors being made even in careful usage of base58-- more than the time itself transferring a base58 address is often insanely frustrating-- you read it, and ... nope, no idea where it's wrong, only that it's wrong -then you try reading the whole thing again and again and again.
[...]....
Missed that.
Thanks for pointing it out.