Good points however I have a few comments. The avro contract with Mesaba is up in 2007. If the NWA pilots and NWA get their wish, the 70 seat a/c will go to mainline flying. Then, why the need for avros? None. The contract stipulates that if the avros are retired they can be replaced with 44/50 seat CRJs 1 for 1. Then, if NWA is operating the 70 seat a/c, their numbers will be a function of the rest of the mainline narrowbody fleet, as are the 50 seat CRJs. So as they expand and contract that fleet, so will the 50 and 70 seats SJs.
I don't think the 777 or 345/346 is really out of the running. They might have been too big for the NWA Atlantic mission, but when the 742s are retired from hauling people, there will be a large market segment gone unfilled at NWA. If they only operate the 332 and 744 across the Pacific they will only have 250 and 400 seat a/c for that mission. They're missing the boat big time with the 350 seat market, especially being an airline that masters the art of matching capacity to demand.
IMHO, NWA can go two different ways. They can introduce the 333 to the Pacific, mainly for interport and Hawaii flying (due to range). This will provide them with 250, 300 and 400 seat a/c for the Pacific entity. Not only will this save them from introducing a new fleet type, it nearly fills the 350 seat gap left in the Pacific fleet. The only problem I see, is that they'll miss the boat with a 350 seat a/c to cross the Pacific (where the 332 is too small and the 744 too large). With a long range 350 seat a/c we could see the resumption of DTW
/SEL and perhaps new long haul transpac flying.
With that said, that's where I think the 773ER or the 345/346 could possibly come into play. Should NWA choose to go this route the winning a/c will be the one that can fill the mission best. That being: aprox 65 WBC and 285 Y seats, full complement of cargo and passengers over a long distance. That's why I think it will come down to the 773ER or the 345/346 (346 most likely). I know engine commonality will come into play, but it won't matter if acquisition, operation and maintenance costs are negligible.
Regarding the acquisition of used a/c. NWA will only do this if those costs of acquiring a new plane are more than the costs of buying a used one and refurbishing it into NWA standard.
Regarding cargo - the new cargo LOA has been signed between NWA and their pilots which will facilitate the growth of the cargo arm in the near future. To what extent, I'm not sure. But I'm sure they're weighing the options of new planes and what type.
It's a dynamic time for NWA and it'll be interesting to see how it plays out.