1,600 miles from the only houses I can afford

You judge a manager by asking for things that are annoying to produce. Ask for their current average days on market for a vacancy, their tenant turnover rate last year, and a sample of an actual owner statement with the name blacked out. Then ask what they charge on top of the 10 percent, because leasing fees, renewal fees, and a markup on maintenance invoices are where the money actually is. A manager who answers all that in writing without getting cagey is telling you something.

Then call two owners they currently work for. Not the references they hand you, the ones you find by asking "who else owns in this neighborhood."

On never seeing it, I'd go once. Three days, walk the street at 6pm, sit in the manager's office. It costs 700 dollars and it's the cheapest education in the deal.

I wanted income without a second job and the thing I underestimated is that a bad manager gives you the second job anyway, except now you're doing it by email at 11pm from a different time zone. The 10 percent isn't the expense that matters, the vacancy they can't fill is. Ask specifically how long their last five vacancies took to lease and what the rents were versus asking.