Sorry, I really didn't feel like looking through the whole thread.. but does this wallet connect to the blockchain network itself like lite-hd wallets and can perform signatures and verifications of other signatures?
Hive Mac app connects to the blockchain directly (SPV), and can sign messages. There's no verify message feature though.
Hive iOS/Web is JS/browser based, so it connects to the blockchain through an external web service, and it has no sign or verify features.