TH and CP are both good, but are different.Personally, if I was choosing breakfast, I woudl look at TH. I like the location. But if I wanted dinner, I would choose CP. There is something quite magical about sitting in the Crystal Palace in the evening. It is pretty any time of day, but evenings are especially lovely. I also appreciate the break because if we are in the MK at night, it means we are staying for evening entertainment.
AS was advised above, you can now use your credits for CRT and for HDDR. I know that this is personal preference, but given a choice of only one, I think I would choose CRT, but if your goal is Princesses, Have you considered Akershus in Epcot? I prefer breakfast, it is AYCTE and is very good, It is expensive so it is a good use of TS credit, even for breakfast. Epcot has so many really nice dining options, that it seems a shame that you have not booked any there. Young people like Coral Reef. THe food and service can be hit or miss, but it is still worth considering, as is San Angel Inn, if you like Mexican. Again, the theme is pure Disney, dining in the Pyramid!
Truthfully, I would look at the buffets, think about why you are choosing them and then explore your options. If you want to do a 2 credit meal, and you know how your family eats, you can think about choosing two TS meals that have larger portions, add an appetizer or two OOP, and then split two meals for 4 people. YOu do this twice and you have one more meal included. You will need to pay OOP for the child's additional meal, but you may be able to stretch your meals and will not be ordering food that you cannot finish. You cannot do this at Via Napolui, or any buffet, dinner show or AYCTE restaurant though, so you will need to really preplan.
AS to BOG 3 times, you will need to be very careful about canceling in a timely manner if you decide you booked it too often. You do not want to be charged with a fee.