"...snip...you can change dates, flight numbers and carriers at any time (for all but the first international sector) for no charge. ..."

I haven't been 100% successful in getting the airlines to agree to that statement. At least a few months ago AA LAX ATO insisted on USD75 to change a LAX-LHR segment from BA to AA. (I walked over to the BA counter, and they stickered it for free, but AA would have none of that.) If they can make up their own rules on matters that obvious, I don't hold out much hope for anything grander.