In regard to needing the full spectrum of abilities I think this is wrong for the following reasons,
We have a large moat around us with a minimum with of 2200 km, this means we can only be reached by air or sea over a considerable distance,which is well outside the combat radius of all but some long range transports or bombers.
This paragraph highlights the limitations with kit-focused issues as opposed to looking a the wider issues on the Red and Blue sides.
First the Red mission and intent needs to be considered, as well as their capabilities. NZ can't really be invaded nor struck (as you say, a 2200 km moat). Which makes it very valuable for a Pacific campaign, just as it was in the 1940s. For a FVEY or similar operation this has huge advantages, especially for operations in the SCS or south west Pacific. Which makes it a valuable target if you can effect it - there's likely to be a bunch of third line enablers there that will rapidly impact Blue forces. NZ's critical vulnerability though, is it's an island. It can't survive without imports and it cannot sustain such Blue forces. And it's unlikely you have weeks of supply. It may be worth trying to undermine the FVEY alliance - especially if combined with anti-nuke information operations or similar. Even better - you cut the SLOC to the west and you impact Australia too - stuff from the US has to fight through or go twice as far. At that range, you can't really use aircraft - so submarines and ships are it. Their advantage is they don't even have to come within range of NZ to blockade.
By not considering the likely threat (surface vessels, not bombers), you've under estimated the actual problem. Bombers come to you simplifying the targeting problem - ships don't.
So as I have always said we do need to improve our surveillance so additional P8's and a basic AEW ability. the E 7 would be a total overkill. The ability to destroy or neutralise what was deemed hostile would be needed and this is more about the weapons than the aircraft, Second hand aircraft in the F15,16,18 range would be perfectly adequate if fitted with a good radar and a modern fire control ability say using possibly the CAMM ( similar to what our navy has) for airborne targets and the AGM 158 for surface targets. F 35 again would be overkill
The Idea that you lose all your combat aircraft when attacking ships with missiles is somewhat simplistic especially with modern medium to long range missiles as you have a directing aircraft outside missile range and the attacking aircraft come in under the radar horizon until in range and either fire by data link from the directing aircraft or pop and fire then drop before any defence missiles arrive. The only stealth required would be provided by the AGM 158
This is borderline naive.
1. The threat is building against stealth aircraft and munitions. Its ships and kit are designed to defeat F/A-18E and F-35C. Plus the munitions they bring. Second hand aircraft won't cut it.
2. Second hand aircraft cost more. Sure, the upfront costs are less, but you'll pay more for maintenance, more for integration and more for a mid-mid-life upgrade.
3. CAMM is a SAM based on an AIM-132. Why would you use that and not an AIM-132?
4. You are marshalling aircraft around the sky with, if you haven't 100% confirmed it, the possibility of a Type 003 or 004 around. Any of that needs AEW&C. Even in Afghanistan, Iraq and Syria - where most of the time there hasn't been a red air force - AEW&C is essential. You want to conduct a precision strike on a modern threat (that's facing forces that use E-2's, E-3s and E-7s) you need that coordination. Sure, an E-7 may be overkill. So it's an E-2. They still cost 2 - 3x a fighter, so if you can afford 28 fighters it's actually 22 + 3 AEW&C.
5. The Red force (and now it's not just China, but anything) will be expecting to go to war against F-35s. You have to match that. That's what their defences are planned to defeat.
6. What are you using to target the ships? You need some form of over-the-horizon solution for your second-hand aircraft - so what sits there being risked? It could be US or similar satellites, but if it's RNZDF then it's a P-8. And that'll die. How does the targeting aircraft remain within line of sight but outside SAM range? You can't just lob missiles over the horizon without some targeting capability.
7. You seriously under-estimate the problems faced in conducting a strike against a prepared SAG of multiple ships. Again, these are ships designed to defeat a US CVNBG attack - a force that has more strike aircraft than your 28 RNZAF fighters.
8. Beyond AEW&C you are still missing enablers, likely AAR (low altitude is going to chew that fuel), search and rescue and EW support.
9 The attack you describe does not align with how the fast-jet drivers I work with have described a maritime strike.
The first priority of any countries of any countries armed forces is to protect that countries sovereignty and the freedom of its citizens and not just to be there to gain brownie points. that is a secondary consideration that you do when you can achieve the main task. The NZ defence force is not an adjunct To the ADF. As for submarines while they are a grave threat to our comunications and I certainly would like more P 8's they are not a threat to our sovereignty.
I repeat our first priority must be the preservation of our freedom before we go after brownie points and while cooperation should where practical be encouraged we are not an adjunct to Australia and neither are our armed forces.
This misses the point of a Defence Force greatly, and highlights a kit-approach to problems misses a lot.
1. A nation's sovereignty does not stop at the border. This is the key to the Defence of Australia crap of the 1990s - if you have to go offshore you can't do that if you think otherwise. NZ has sovereign interests in a multitude of places off the small islands, including the Persian Gulf, Singapore and it's surrounds, Antarctica, the Pacific Islands, Australia and the Pacific out to Hawaii. The NZDF cannot defend that.
2. The way it can is through making alliances (and, in DFAT friendly language, diplomatic agreements). To this end, you will become an adjunct force to Australia and the US. Which is a good thing! You support US operations in Iraq and Australian operations in Timor Leste (like you have) you prove your value to them and when the time comes it's not NZ defending the area in point 1 - it's the US, Australia and NZ. Which makes life easier!
3. This will demand forces that can work together (so probably not second hand fighter aircraft) and sometimes going to places you'd rather not in support of your allies. Of course you won't agree on everything - but as it is NZ and Australia have an excellent reputation among senior US military peeps because we call them when they need it. Some have even suggested that we exceed the Brit capability in this over the past decade or so.
4. Like it or not, you will almost always fight beside us. We cover your western flank and northern flank, we share enormous amounts of culture and history and have similar needs and goals. I've sat in meetings where (at a high level) we have discussed, with NZDF people, the idea of giving up major chunks of NZDF capability (think entire Corps or fleets) because if the NZDF ever needs those capabilities they'll be alongside Australian's who will have brought them.
5. This doesn't even touch on the other, non-military national security issues that you've missed that see NZ publicly sharing and conforming to other nations.
6. None of this should be shameful or upsetting. The the biggest Army's of the world couldn't stop catastrophic invasions in 1940 or 1941, and their tactical and strategic situations were a magnitude easier than NZ's. France and the USSR needed allies to win their nation back. Furthermore, despite what (4) may sound like - Australia does this! We can't defence our area's of interest, we never have been able to. So we look to a strong ally with shared values - the UK and then the US. The ADF cannot defend Australia's interests alone. But with help, it can. NZ is the same.