Take a single rope. Absolutely no need for doubles.
Take quick draws.
No trad gear required.
Take a stove. Not much in way of facilities at hangdog (though I dont know about the cabins).
Takaka has supermarkets and enough organic produce to keep a feral happy. Try the mussels at mussel inn.
Visit Rawhiti (?sp) cave on a rest day. Go swimming in the river. Hitch to the coast and walk some of the Abel Tasman track.
Hangdog is a couple of kms from the shops, but pretty easy to catch a lift in.