Thanks, @James Stinnett and @Jason DiClemente!
To James, we could go either way with regard to making the largest unit of the 4-plex our primary residence. It would be smaller than what we're used to, but it's a great location and the current tenants seem like a good bunch. If it goes through, we'd start an LLC to manage the place, so if we do move in and pay rent to our own company, we'd actually be paying ourselves, right? I guess in a way, we'd be doing that in any home we're paying for, but we'd also be getting paid by the LLC to manage the other rentals, so it would reduce our living expenses even further. We're obviously not CPAs either, because the $500K exclusion from long-term capital gains taxation hadn't even occurred to us. So yeah, if you're right, I think we could tough it out for a couple of years! :) And yes, we would be doing some rehabbing along the way. Thanks for the thought, though, we'll definitely be looking into that!
And to Jason, I get what you're saying about maximizing cash flow vs aspirations to scale up quickly. Both options sound pretty good, but we'll have some additional funds down the road to scale up with some cheap SF flips. First, we need to get where the action is so that we can keep an eye on the area and move quickly when opportunities present themselves. We've got a good contractor willing to work with us, so look out, Pinellas County! Thanks again, guys!