Hey VGolfer,
you are right to be concerned by the supplier's statement that "whatever you do moisture will cause pointing/cupping"...this is the first excuse they'll use if anything does go wrong...(nuthin to do with us or the boards..Its the moisure in your house mate!). If you live in East Sydney they'll probably be right.
Anyhow, all the advice on this message board is excellent but the humidity level in your house/subfloor and how it varies across seasons will be a big determination of how flat your floor stays. You will always get some shrinkage and swelling, although this will be a lot less if you run reverse cycle airconditioning in your house most of the year.
THe best way to reduce cupping is to cut and lay your boards unfinished and upside down, screwing down every 5th one. Then leave for 6 months to acclimatise. Then unscrew, flip and nail/glue and finish.
I'm assured this works but of course no sensible Minister for Home Affairs would ever put up with this for 6 days let alone 6 months so am not speaking from personal experience here...
Anyhow, whatever you do, if things do go horriby wrong you see your boards starting to cup, either ignore it (and just like rising damp it will go away) or go buy a small humidity controlled dehumidifier ($500) and stick it in your subfloor. :-)
