It's funny how people have been asking what the differences were for months, and iRacing staff assured us that there weren't any, and now all of a sudden they've "fixed" it. It really annoys me how they just won't admit to any imperfections at all until it suits them.
Is there any such thing as an offline test session in iRacing? You just connect to your local machine.
Yes, it only does the authorization check if you click 'Testing'; if you have the L/Q/S bars up you'll see it doesn't touch the network after that.