Probably very, very little. I don't mean to have a go here - but you come off as very ignorent with these kinds of comments. In the current squad there are no players who were born in the Pacific Islands playing for the All Blacks. Further more I challenge to you name more than three players in the professional era (since players could play for multiple international teams beforehand) who weren't developed through the New Zealand rugby system - starting from school level. Samoa on the other hand had 15 New Zealand born players in their squad - all of whom came from the NZ rugby system (some players who were born in Samoa also used the NZ development system). Having brown skin doesn't exclude you from being a New Zealander - but I'm not sure what other basis you would have for your argument.
What is happening with Australia is very different - as they are recruiting out of our development system.
Unfortunately I disagree. Players like Pocock, Genia, Ioane, Cooper etc fine. They are immigrants but they learned most of their rugby in Australia and I'm sure are proud to be Australian. However when you have players like Henry Speight, Mike Harris, Tim Fairbrother etc being recruited with the chance to play for another international team being the incentive - I don't belive that is moral. It's taking advantage of another development system rather than investing in their own - and for the number two side in the world it's embarrasing. The point that those players wouldn't make the All Blacks is irrelavant (and I still don't rate Mike Harris), it's essentially allowing a competitor to invest in a player and then work around outbidding them. I don't believe this kind of 'professionalism' should extend to international teams. Mike Harris being allowed to play for Australia because of a grandparent...
Sadly - New Zealand is constantly being pillaged for rugby players by other teams - it's no worse than Riki Flutey or Thomas Waldrom playing for England.