It looks like it is more of a case of the Dutch letting other people govern it, as long as they do exactly what the Dutch want. There where other parts in the Dutch East indies where that happened, like (I think) Yogtakarta on java.
That si true. The Netherlands still had some work to do in the Dutch East Indies during the 19th and 2th century. Still i believe that if you add Belgium to the Netherlands (possibly even just Flanders) the Dutch would be able to either finsih Indonesia earlier or at the same time colonise other areas, like some pacific islands (or the Dutch gold coast). Mind you, I am willing to admit that they won't be able to be another Britain or France. I do believe New Zealand (cool as it might be) would be overextending the Netherlands (besides possible diplomatic problems with Britain/Australia). If you want a Dutch New Zealand you probably need a POD during the Dutch republic (including a different approach to colonization). And even than a Dutch SW Australia is probably easier.True, but bear in mind that that part of New Guinea was definitely not under any actual control by Tidore until the turn of the century, so it's not as controlled as it looks.
True enough, but the Netherlands is the closest thing to a formal ally the British have on the Continent in the early Nineteenth Century, certainly after the connections with Hannover, etc. are no longer in place. May actually be the UK's interest to strengthen their ties with the Netherlands...
And as has been pointed out, the Dutch have a huge project in what became the NEI, as do the British in Australia; conversely, a "Dutch" settler colony in the Pacific might actually make the NEI "easier" in terms of a European population in the region to draw on for personnel and supllies - think of "Nieuw Zealand" as the Cape or Natal to Indonesia as the Transvaal, ZAR, Rhodesia, etc.
Another possibility, I suppose, simply from a point of geographic continuity and defensibility, might be to trade Dutch Borneo to the British in return for a free hand in all of New Guinea, at least before the Germans show up. Probably not much a trade in terms of economics (have to be before the oil industry develops, obviously) but it does make some sense in terms of geography.
Best,
Interesting. All I'd say is that the actual raw numbers of British migrants on the 19 the century were low,to NZ, which was end of the line so far as migration destinations. So the vast majority of the current NX European population are descended from this group.