All things being equal on the asset side, the operation and systems put in place will make or break the performance of the investment but at this point that has almost nothing to do with real estate. 

Some towns require a nightly online form to be filled out for any non-residents who are parking their cars (this is easily automated from an operational standpoint).As the MTR market becomes saturated over time, those who have separated themselves from the rest of the "competition" will continue to perform well by having an outstanding listing and all the MTR-specific amenities.

Best Buy also seems like a strong bet, but they only sell single-game machines.

The return on equity is probably very low considering they are paid off so maybe explore refinancing or selling the lowest performing one(s) or your biggest headaches to reinvest in more lucrative deals.I noticed you also used a metric of number of rentals to attain your goal rather than $$$/month.

Quote from @Benjamin Finney: Chris, interesting niche on non-performing mortgages/ rtl's.

Always perform thorough market research and verify the numbers on any property you consider.

It simply means that you agree to let them perform a 1031 exchange which starts with the sale - not that you have to help them finish. 

It under performed, but it was my first flip.

But I agree, seller's best bet is to buy using a conventional loan if they can qualify. 

The quicker you can take action on the high dollar value decsions the quicker you will be able to grow.For sure take the time to setup the right foundation, but keeping it simple and easy when you are getting going is a safe bet!