ORIGINAL: jaafit
Most of the airports in G3 come with multiple airplane spawn locations. To change which airplane spawn is used, you must change the camera position. Look for "Camera Position" in the "View" menu. Clicking that brings up a submenu of all the pilot spawns in that airport. Once you choose a pilot spawn, the plane is placed at the closest plane spawn. Press 'X' to cycle through the list of pilot spawns.
If you want to add your own airplane spawns or change existing ones, you may do so in the airport editor. Click "Edit _______ (airport's name)" in the Simulation menu. Once in the editor, look in the "Airport Editor" window for the various plane/pilot spawns. They are usually in a folder called "Control Objects." You can move/delete/rename them just as with any other airport object.
The old G2 used to allow you to change pilot position with the mouse. I take it, that is no longer available?
I too have been frustrated by the inability to easily change the view position. My normal flying is done from pilot left to pilot right takeoff, using a left turn pattern. I like to start my takeoff from the end of the runway at the pilot left position and use left to right. The default appears to be place the airplane in the middle of the runway and takeoff is right to left. I played with spawn and still had a problem.
BTW, a little off the topic. No one has answered the question why G3 is extremely touchy, especially during ground maneuvers.