The "keyboard input emulation" in iVault is designed specifically to circumvent keyloggers. Having said that, keylogging technologies are constantly evolving, so nothing is 100%, not even human vigilance.
Also does it leave any disk traces of the password given an HTTPS connection?
I don't see how it would. The login credentials, regardless of HTTP or HTTPS are read and suecurely decrypted in memory and passed to the appropriate login fields. There is no disk activity involved and can't think of a circumstance where it would be required.
Cheers,
Ewen :-)