OP - based on what you have said, TK will be your friend. What's good about TK, AFAIK, is its low requirement (37.5K for *G), as well as 2-year membership and the soft landing.
The biggest problem is the fare class uncertainty. However, assuming you can earn at least 50% on each flight, a RT NYC-SFO each month should be able to yield 30K status mile with TK, even with BE. It can be even more if the tickets paid by employer are more expensive.
Of course - 1 thing you will definitely trade off is UA's E+ (extra legroom seat). But it is more difficult to become a UA Gold. And the loss of such benefit can be solved by an E+ annual subscription.
While I understand how much you prefer JFK. I believe you will have a better outcome if you return to EWR.