Sorry, but Opera Mini support and Wikipedia both say you're wrong here. They explicitly state that all traffic from the device to the server is compressed and encrypted (as of version 4.X), and that SSL encryption starts at Operas server. If they did it any other way, they would not be able to offer the services they do, like image shrinking/de-res and text compression.

I would be very surprised if it's not mentioned in the legal section of the terms, be that with the software or in the documentation on the device if it's shipped with it. Since you clearly are wrong on your other point, I'm a bit skeptical at accepting your word on this as well.