You could transfer your existing IRA to a self directed IRA or Solo 401k and invest in real estate (or anything else the IRS rules allow for).  

You can only allocate a couple % for this - the other regularly recurring expenses like roto rooting, regular tree trimming, asphalt sealing, etc can all be allocated as part of your diligence and be pretty firm year over year.

All the cash flow from my existing properties stays in the bank account for each LLC.

I have to imagine a few active groups exist there.

This favors the conventional loan because when you refi down the road, you'll be stuck in the interest rate environment that exists down the road, whereas you'll keep today's rate with the conventional.  

They exist and probably do in a surprisingly large number when you look at the whole state. 

Sometimes the existing tenant is neat enough to do showings while they're still there.  

It wasn't until I hit 6K per month that I got consistent and quality responses that I could reasonably make a living at.3) I don't do yellow letters as I believe that market is saturated here.

Your best candidates for seller financing are existing landlords / absentee owners.  

Turn of the century buildings were built with materials and craftsmanship that just doesn't exist today.