Hopefully I can help you a little bit! By 'cousins', we mean the waiters/waitresses at 'ohana. In order to make us feel like family, everyone refers to each other as cousins.
As for bounceback, if it works the same as last year (and so far it is), you can book now and CAN make changes as necessary. For free dining this year, we booked it LAST year. In the past year, we had to change our reservation 3 or 4 times and had no trouble! When you stay at a Disney hotel during the special time period (in this case it's late August/September), you had the opportunity to book a trip for next late August/September). We just phoned the number listed on the paper in our room and we're all set for 2009. If you have to cancel, I'm sure you're fine because it seems to follow the same cancellation policy. HTH!
Forgot to add that it seems to be for all (or at least most) WDW hotels from the values all the way up to the deluxe hotels.