Ok, here's a couple more thoughts:
-The upper NorthI. should have a very smooth west coast. That bump you have up in northland should be on the east side, thought justifiably it could be removed altogether.
-Lake Taupo, which I think you've tried to represent by the water formation on the end of the northernmost river on the north island, should be in the very centre of the island at it's thickest width. A suggested river tributary to it would be the Waikato, which I will mention further down.
-That mountain in the SE northisland is out of place. Should be one tile further west, with lake taupo directly north of it. If the island is considerably more resource rich than you want, that could even be made into a volcano. It's eruption in 1995 was sizable, and this would certainly decrease the value of the place if you stick with your random destruction of nearby improvements idea for volcanoes.
-The coastline on the tile one west of the wine (in the eastern NorthI.) should be a lot smoother. This is probably caused by the river there, which I think should be moved to where the Coromandel Peninsula is to represent the Waikato river (biggest river in the country). That is, starting on the west side of the tile with fruit (the river is currently on the east side of that tile). This would also go towards making a greater distinction of that being a peninsula.
-You're right on that wine resource. Wine's pretty big in the south too, but I forgot about the eastern NorthI. when I mentioned it before.
- Possibly remove that tile which connects the two islands? That mountain right next to it seems unnecessary, especially considering Mt Taranki isn't included. The resouce on that tile I just suggested removing could be moved there if it is to be kept and the mountain removed.
-Timber is big here. If it comes down to coal vs timber, I'd go with timber.
-The bottom of the south island is very fat. The width should be relatively close to even the whole way. Ideally, it would be slightly larger in the southern end than the north end, but without making NZ much bigger than it is, this can't really be done without making it overly big.
-You're right, the two islands are at different angles. If you were to use the NorthI. as the base (as it's positioning looks good, thought I haven't seen it in relation to Australia), the SouthI. should be angled about 20 degrees or so further south. Though this might be achieved via removing those 3 tiles on the west side of the mountains.
-It's tough keeping those mountains accurate there, as there is significant land on the west side of them, but on a 3tile wide island, they're best on the westernmost square. If it were 4 tiles it would be accurate one tile in, but that would throw the island out of proportion with the rest of it, and the rest of the world.
-Those clams should be literally off the southern tip of the island, between they're too far east for realism, though that does put them very close to the fish down there...
-If the SouthI. is moved that one tile east, then I'd move StewartI. with it.
I'm already measuring up exactly where I want my settlements down there

The only major issue I now have is the angle/width of the SouthI. Otherwise, eveything else is relatively minor, and I'm not at all fussed on the specifics of fertile or arid grassland or whatnot. I'm gonna go find a New Zealand map to play a game on now
