It defeats the purpose if all you do is get players into the NRL.
The point of getting a team into the NRL is to give their country a focus and bring together all the various tribal groups into a national, cohesive group. They're not looking for more players in the NRL, they're looking for a team that they can call their own.
It has to be the "Papua New Guinean <insert nationally significant symbol here>s" team. Anything else will defeat the purpose.
By being a national institution it would also be bypassing a lot of the other requirements of a football team. Essentially the government will see how much it costs to run a team and then write a cheque. After that they will try to recoup their costs in whatever way they can.
For PNG I'm thinking that means NOT relying on tickets sales (people rarely pay to watch footy up there from what I've heard, they just attend enmasse), it means getting 'goodwill' sponsorships (companies who wish to continue mining can cough up the cash, pay it through extra taxes or find it a lot harder to function for 'security' reasons) rather than necessarily sponsors who're trying to sell something, and it means taking 'security money' from AUSAID and putting it towards 'nation building' in the form of their new footy team. Which will then bring Krudd into the equation.
As far as players go, it will become one of the few ways young blokes can escape the life they're born into so the desperation and numbers will be there, not to mention a government funded system to uphold national pride that will train players the way we train Olympians- except this is the only gig in town so the whole countries resources will go into this one sport.
If a new stadium is built it would no doubt become security central. Fences may be a novel addition to rugby league but no different to many soccer fields around the world, corporate packages would be sold to mining companies making their companies a more attractive place to work which would then lead to MORE security, away team accomodation could be built into any such precinct if anyone was going to stay the night and no doubt a dirty great big wall around all of that to insulate it from community trouble (again, see soccer for examples).
The real problems-
Corruption. This thing will be run by the government and the government is dead set corrupt. How that will play out is the real big question mark over this whole experiment.
Players wont move there. Accept it. It's no place to raise a family when you can just move to Canberra or somewhere else. But also think of this- you're pretty much going to have the PNG national team playing week in, week out. Take the domestically based Kumuls, give them NRL intensity fitness and a home ground advantage that's up there with visiting old Lang Park during Origin in the 1980s. They should be able to hold their own. If they then dont move away to play for other teams...
Security- having the team in the NRL will put the media focus on Port Moresby. Port Moresby's crime will deter any real away support so you can forget a tourism industry. It will also add to the colourful media scrutiny of league. Sure, it wont be footy players behaving badly, but it will be there in the background. Having the spotlight on Port Moresby will be good from an international perspective as it will put the PNG government under the pump to improve things perhaps moreso than having a team will unite the country. It will also give the Australian government more leverage- 'get your act together or we take away your football team'. However it would complicate the simple business of showing up and playing footy week in, week out. Good for PNG, complicated for NRL. And you certainly wouldn't want the PNG equivalent of hooligans...
But realistically, if they can guarantee the money and will accept the fact that they'll be only using home grown players (even if it puts them near the bottom of the ladder most seasons) then I dont see why not. Give 'em a chance in the QLD Cup and see what happens. Just make sure they set it up as if they were going for a fair dinkum application for the NRL, right down to stadium, security, etc, even if it takes a few years (the way the Titans did) THEN make a decision a few seasons into the QLD Cup with no guarantees.