Boosted by a diverse economy, relatively low cost of living and above-average population growth, Columbus had the second-highest rent growth rate in Ohio, trailing Toledo (3.8%) but outpacing all other metros in the state, including Cincinnati (3.0%) and Cleveland-Akron (2.2%).

If not adding that added square footage will give you a boost when you go to refinance. 

Each of these variables will dramatically change the advice I give the individual asking me this question.

There is no way I could pay that kind of a price for a SFH anywhere in the U.S. now since home values have increased dramatically.

But I think there is an optimal point - one shouldn't go too expensive or high-end where you could end up dramatically reducing the pool of potential tenants.

When interest rates rose dramatically, passbook savings rates also rose.

We agreed to let one tenant out of her lease early because she's way under market rent, so this gives us a chance to boost it by like $300-$400/month.

Your trade off for receiving interest is dramatically lessened security of your funds.  

If you can't submeter, then I would suggest structuring the lease in such a way as to include utilities based on current consumption and allow for increases if utilities dramatically increase.  

The have had changed dramatically over the past 20 years.I have never found banks to play games as long as you are organized and qualified.