about WhatsApp and a password being sent;
All I got when using it via nitroid on my n900 was a text message with "+447624803777: WhatsApp Code 000".
The code are just three numbers (not 000 of course) I couldn't find related to imei# nor telephone#.
Whether this is supposed to be a password or not - dunno.
...Oh yea and I didn't got it to work on nitroid to actually send the messages. At least they are not received by the contact as they are with Symbian based on WhatsApp on a e71.