Señor Meyers,
My opinion, seeing as both you and I are in the same boat, one right behind the other on the seniority list... is this, and buddy have I been thinking alot lately.
Who really knows how long this thing will last even for us in the top 10, you know? That taken into account, I would not give up the seniority number. You've come up with a few things and you have some options up your sleeve... one of the most appealing is the one about a corporate position in the future, once you have more flight time experience.
I think that we should always be looking for advancement, or atleast the possibility of it. Whats the point in moving laterally, from regional FO to regional FO? Specially if it is going to just put you at the bottom of a seniority list. I believe that an opportunity to go to a corporate pilot position is a considerable advancement taking in mind QOL and many other factors.
Personally buddy, might not be too bad to take that non flying job for now, and spend time with the lady. Support her while she finishes her stuff, also then you could ask for some understanding and support on her part when it comes for you to either return to PSA or head to another flying job. Save some money working outside aviation now, so that if you decide to come back to PSA, you have something to help mitigate expenses or even just as a "rainy day" fund. You are a flight instructor, If i were you, Id instruct on the side, by urself, not through a flight school...they take too much of your money. Charge the same that a schools flight instructor would cost and you can keep all that cash for yourself.
I believe that a lateral move into another regional may not be the best idea. Thats just my opinion specially since we are at the top of recall. Of course, I know that just cuz we are numbers 7 and 8, we have no idea how long it could take, considering that, I still wouldnt put myself at the bottom of another regional list.
Take care buddy