My current house is at a lower interest rate and got appreciated a lot. 

Cons - you're paying interest on a higher amount and/or your rate will be higher with a higher LTV. 

With that low a response rate I recommend revisiting your rent, how does yours compare with other similar properties within commuting distance of your house?

CU and small local banks usually have the best terms/rates.

Never get into cap rate???

What they can do instead is a quick and easy cash out refinance since rates are dropping back down.

I started with MLS deals but after the first two I was able to start sourcing my own off-market deals.I found doing this allowed me to get houses even further below market rates and I'd be able to cash out more than just buying straight cash from the MLS.Keep it up man!

These areas have different tenant pools, turnover rates, and varying cash flows.

The numbers I've seen on P & L's recently are still good, still better than long term SFH's but usually they are at about a 50% vacancy rate.  

I feel what you want to do and have done the same (operated units at a 'non profit' rate), but none of my single parent tenants were in a position to or even had the desire to own.