I’m the first one to say that the official nem wallets are far from great, I just don’t see how any of this relates to security itself, which is what your original point seemed to be. Passwords are secure if you chose strong ones. None of what you’re suggesting makes anything more secure, it just makes it more convenient to use.
On a side-note: Biometric scanners are mostly just a cover for an additional key hidden somewhere in the hardware. You can’t really use biometric data for encryption directly, because the output of such scanners will never be 100% the same.