Try here:
http://www.flyerguide.com/wiki/index...Rules_%28AA%29

or here
http://www.aa.com/aa/pubcontent/en_U...ward_Chart.jsp

to start. Within the aa.com URL, there is a link to FAQ's about all partner awards.

I'll let more experienced FT'ers directly answer your questions.
To note: I've just recently booked an all-partner award myself and made a date change. Since it didn't involve any routing changes, the AAgent made the change immediately with no fees. This is one data point, I know, but thought it might be useful for you.

Happy travels!