by dave3cu » Tue Jul 23, 2013 9:44 am
FSX has a control mode called 'mouse as yoke'. To learn more goto the FSX Learning Center, > 'Key Topics' > 'Controllers'. Under 'related topics' select 'using the mouse'. (Note: the key command for 'mouse flight control (on/off)' is (crtl+y), not (shft+x) as stated in the Learning Center.
Go to Settings>Realism and enable 'Auto Rudder'. This will tie the rudder/tiller to the ailerons so you can ground steer with the mouse as well as provide 'auto-coordinated' turns when flying. This is also useful if you're using a joystick with no rudder axis.
Go to Settings>Controls>Calibration tab, Controller type' Mouse Yoke' to increase the Sensitivity and reduce the Null Zone for the axes to your liking.
Not sure about the meaning of your last question. Are you asking how to convert a nose/tail non-steerable wheel (castor) to steerable (tiller)?