If some or all of loans are or could be at very low interest rates (< 5%, for example), it might be less financially savvy to pay back those loans as fast as possible then, say, invest the extra money in other ways that might generate > 5% returns (stocks?

There are many ways to add value, the trick is adding enough value to be able to refi and pull out most or all of your cash investment, and still have a property that will cashflow.

Might be able to get another 4 inches if you use the interior wall cavities.

You Rollover some or all of your Traditional IRA into the new 401K5.

Either you get a handyman, or all in at property manager.

We'd love it if you could join us at any or all of them! 

So if you buy such a place, can you only evict one tenant or all the tenants, if you say you want to live in all of them and would not rent for 3 years?

During my tenure, I've had property management oversight of my Dallas area multifamily portfolio, while assisting with acquisitions and dispositions of assets as well.Prior to jumping into real estate investing full-time, I spent over a decade at Seagate Technology where I held senior leadership roles in Marketing, Product Line Management and Sales.In addition to being a licensed real estate broker in Colorado, I have a degree in Marketing from Oral Roberts University in Tulsa, Oklahoma.

Are you looking for a specific cash on cash return, using the gross rent multiplier , cap rate or all the above? 

If we want to get some capital back we will sell some or all of the loan to an investor looking for more passive income.2)  These borrowers would not qualify for a bank loan but are solid people.