Having operated in and out of Taupo over the years on various op's in various a/c I never had any hassles.
Parachuting stops for all IFR traffic and wayward VFR's, the locals generally know better than to use the crossing grass as this is pretty much the DZ for some parachute ops, the Heli's and ag. a/c are mostly low level so out of the way of most traffic, the part 135 guys know the area and seem to have a level of situational awareness not always seen elsewhere, anthing about 5000AGL is controlled anyway so whose left? Lower level itinerant VFR? Im sure they dont represent a large % of movements but if its a half decent day there will be someone else out (usually the jump op's) who are good at helping them sort things out if there is going to be a problem of some sort.
As has been said before the only way to be 100% safe would be to keep the a/c in the hangar.
I think you would be more likely to have a near death experience going into the likes of Ardmore or Milford than Taupo.