Some features have been added to the CRJ700 family that are not found in real live but make things more convenient in a simulator environment. You can en-/disabled these options via the config dialog. Click on the "Bombardier CRJ700" menu and select "Config".
The real CRJ700 has no autothrottle although its engines are controlled by FADECs. Thrust is controlled manually with the two thrust levers.
For beginners and the lazy one we re-included the autothrottle as an option. Select the corresponding checkbox to get the magic button. Believe me, once you learned to fly this aircraft you won't have problems with manual throttle. It is not necessary to fly exactly the same speed all the time.
Normally, the rudder pedals can steer the nose wheel only up to 8 degrees. For taxi the pilot uses the tiller handle to his left for full 80 degrees. In FlightGear you can use "W" to open the tiller dialog and "q","w","e" to set the tiller. Some pilots do not like to use the keyboard for this but prefer to use the rudder pedals - here you can enable this option.
Having this option enabled is dangerous during crosswind landings, where large rudder commands are needed. Make sure your do not push the rudder pedals to much once the nose wheel is on ground or you may leave the runway unexpectedly.
If you have a throttle quadrant connected to your computer, you might want to map the mixture lever (which is of no use in a jet like CRJ700) to the speedbrake control lever, instead of using the hotkeys or 3D cockpit lever. Minor detail: the real lever has detents for 0, 25%, 50%, 75%, 100%, while this optional mapping allows any value between 0% and 100%.