Matanga is a great introduction to Fiji for sure, the fact that you went to the north (well off the beaten track) says a lot, it's more out of the way and more natural because of that as it's less affected by tourism and luxury hotel chains. That tree house looks gorgeous.
I've heard of the reef walls in the north but have never been there to dive, I have been to some great dive sites though, there are so many throughout the south pacific so long as you keep away from heavily populated towns and cities.
Where do I start with the grog/kava/yaqona...my longest drinking session on Kava was 13 hours straight, I pretty much crawled home from that one...lots of drinking games to be had, especially when my Tavale's (my wife's sisters and brothers for example, someone who always teases) are involved, that's when I need some Karua's (other's married to my wife's brothers and sisters sharing a common enemy! classed as real brothers and sisters). I am the reigning champion Kava drinker with my wife's home village (not where we stayed) and I have various challenges to look forward to when I next visit...
One of my many Karua's lives in a village right next to a beach and reef (Nauouo, Ovalau), when he wants some fish, and a taboo has not been imposed by the local chief (another cool thing to stop over fishing), he picks up his weighted circular net when the tide is out, and waits for a glimmer in the water, within 10 minutes he'll come back with a net full of sprats/sardines that sort of thing. They then go onto a piece of corrugated iron laying on top of an open fire and have a chilli/lime marinade poured on to them from time to time, yum tum
Gotta love the fresh food!
Here's some very old pics of some of the family and the places I stayed:
http
/www.flickr.co...57594069163027/
Oh, not sure if you like rugby or if you can get a chance to watch it, but the world 7's rugby tour is on at Twickenham, England this weekend, it's televised on Sky Sports here (I think) so you may be able to watch it. 7's is THE game Fiji excel at, my wife will be making A LOT of noise this weekend

The Rugby Union site for it:
http
/www.rfu.com/T...ns/LondonSevens