Hi @Paul K.
It looks like you've thoroughly thought this out and that you are also getting some good advice from other BP members.
Throwing my two cents in:
* I agree that if you decided to buy here, plan on selling the unit when you PCS off O'ahu as the most likely outcome unless you want to feed the property. Depending on type of property, overall real estate historically appreciates on O'ahu from 4.3%-4.7% annually (can be higher in the more desirable neighborhoods) - but obviously no guarantee this will continue. However. . .
I'm amazed how strong the market is still on O'ahu despite the higher interest rates. I've had quite a few buyers postpone their goal of buying here because of the higher rates, but I still have many clients looking and I'm still seeing high demand for real estate and multiple offer situations are not uncommon. I just listed a nice 1 BR non-STR unit in the Ala Moana area - seller had multiple offers and is in escrow in under a week. If the deal closes, it will be the highest priced selling unit in the building in over 1 year.
So the market is still very strong despite the higher rates. And with the lack of inventory, if rates do go down, and there is no major US or global down turn, it seems like demand for housing on Oahu will only increase - thus leading to higher home prices.
* Also, please note it is very difficult (but not impossible) to find quality off-market opportunities on O'ahu. I regularly solicit off-market properties hoping to find opportunities for clients but opportunities are few and far between and only very rarely are they "deals."
* Lastly, if you think you'll likely be here 4+ years, and eventually want to retire here, personally I don't find it that risky to acquire a home here while you are based here. Based on historical data, you could have a nice chunk of equity by the time you PCS off O'ahu.
Wish you well and if I can provide you any information to help you with your decision, I am here to serve you. Good luck