From my understanding there are suites in Tonga accept for one room they can use if someone in the suite next to it doesn't use it.It is like a connecting room to the suite beside it. I believe I read that they have morning offerings , snacks and drinks (soda juice, and water) available in Tonga but for the evening offerings you have to go to the other concierge building.
I believe Tikiman put a post up with all the walk times on it somewhere on here . do a search and you may be able to find it . it was under something about the rehab of the rooms. I think it was 3 mins to walk for Tahiti to GCH but I am not possitive that wast the time.
Hope this helps!
Sharon