Yes, you'll pay to change the origin, unless you're executive platinum. Just to put this in perspective, some other airline programs have fees for any change at all including just changing the flight time or date. AA has a relatively friendly policy.

In case this helps, there's a separate thread about award rules.

http://www.flyertalk.com/forum/ameri...-9-2009-a.html
http://www.flyertalk.com/forum/ameri...ld-awards.html

And another for special distance-based awards:
http://www.flyertalk.com/forum/ameri...er-awards.html