However, I did my own research on them first, and then sort of "interviewed" them in person before signing on.  

You will have to review the interest tracing rules with the IRS.You only recognize it when you sell.

Its common to interview a few brokerages too see which one best fits your needs as an agent 

If so you can go around and interview the brokers at all the different firms.

You will not imagine how many jack of all trade accountants forget to add closing costs, appraisals, inspections to the basis.There are many accountants on BP who work with clients remotely.You should interview  a couple and see who is a good fit for you.

During screening interviews make it crystal clear that as a professional landlord you do not tolerate late payments for any reasons.

I heard an interview about this 2-3 years ago (some online guru, can't remember).

@William EspichI would start by checking out Zillow or Redfin for any agents you can interview.

Those fees all sound within reason but it's definitely in your best interest to interview several property managers.

Buzz feed and MSN just haven't interviewed them).