I'm a little unsure why you are ruling out UA? You can credit every Star Alliance flight that's in a booking class that they give credit for. UA's program is significantly more generous than most for cheap fares, at least you usually get something, where many other *A programs have loads of 0% credit fares on partners. Your one and only negative would be the PQDs which as you have noted do not credit for *A partner flights, but are you flying enough to make status anyway if PQDs were not a thing?

The other one with a quite achievable lifetime status is OZ, however I do not believe they extend the benefit to spouses.

In the end, if you really want to try for lifetime status, you should probably make a concerted effort to fly UA for your overseas flights, but even if you make Gold every year, it's a 20 year effort. Who knows what the landscape is going to look like in 20 years from now. As for PQD to reach Gold on UA, it's just a $6 annual spend which you'd easily have if you put just a few of your overseas trips on UA metal. You can also get the Chase credit card and spend enough to get the PQD waived (up to Platinum).