Here is an example of what we did in July 2011:
5 nights, 2 adults and 1 child (although DH left a day and a half early)
Day 1 (Night 1): CS
Day 2 (Night 2): Crystal Palace breakfast used 2 adult and 1 child TS
Day 3 (Night 3): Sci Fi lunch used 1 adult TS for burger and 2 milkshakes(and paid for one burger and side of onion rings out of pocket)-all 3 of us ate
Ohana Dinner used 2 adult and 1 child TS
Day 4 (Night 4): Tusker House breakfast-2 adult TS, 1 child TS
Cape May Clambake-1 adult TS, 1 child TS (only my son and I there)
Day 5 (Night 5): Chefs de France lunch-1 adult TS (my DS and I shared)
Day 6: 1900 Park Fare breakfast-1 adult TS, 1 child TS (only my son and I were there)
So we were able to spread our credits to 7 TS restaurants
So obviously, we did not share at the buffets or all you can eat, but we had no problem using partial credits at Sci FI and Chefs de France. At Sci Fi the server had no problem with getting us two milkshakes at once ...at Chefs, the server had no problem with us sharing the prix fixe meal.
Doing this my 5 year old didn't have to eat any TS kid's meals (he either shared adult meals with us or ate what he wanted at a buffet)