I've made changes to my reservations in the past and have never been charged the $50.00 change fee. However, every time I've done this, I've been spending more money which is the same scenario as you have. When I call to make the change, I say something like "Surely you aren't going to charge me a change fee since I'm spending more money." I don't know if me saying something makes a difference or not but I figure it doesn't hurt.
We had a room only reservation for our first two days and then had a
free dining package for the other 8 days. When you call to make the change, be sure to tell them that you have a room only and then a package reservation and that you'd like for them to make a notation that the reservations are "continuing". Then, about a week before you arrive, call again. When you check in, tell them again. I was able to keep the same room for our entire stay.
There's a marina at the CBR and we like to rent a surrey bike and take a spin around the resort. It took us 30 minutes to go around the resort twice. My son rented a bicycle and rode around the resort 6 or 7 times and could have done a few more laps but we needed to get ready to go to a dinner ADR. I posted a picture of the marina sign with pricing on the CBR picture thread.
There's also several types of watercraft available for rent at the marina....sea raycers, pontoon boats, sailboats, etc. Also at the marina, there's a pool table and playing is free of charge.
I forgot to look and see what ages your girls were and can't remember from your previous posts. There's a playground in the middle of the island which is a new addition. The kids' chicken nugget meal in the food court comes in a sand pail with shovel which can be used later to make sand castles on the beach.
Hope this helps