Yeah the rudder-on-the-ground thing is a huge pain. As far as I know, they're aware of this, but I thought it would be fixed at this point.
Just figured out how to map the yaw controls to the keyboard (I don't have pedals). It gives me control, but it seems way too overly sensitive. I think it's impossible to get off the ground unless I have pedals or something...
If you enable autopilot, then press "A" when you want to takeoff, you can have the AI takeoff for you, then press "A" to disable it once you're in the air. Workaround until it's fixed