I've watched his company explode through his hard work and treating people right.

I completely agree with @Tim Herman and @Grant Delmonte about how you should proceed if you're going to handle the property management for your future quad yourself.However, I think you've asked the wrong question.If this is truly going to be an investment property, then I strongly urge you to treat it that way from Day One: Hire yourself a professional property management company.For one thing, you simply don't know what you don't know, and any time you spend learning to be a PM is time not spent finding more great deals.

You’ll also have to treat left-behind property in accordance with your state laws.

Property Management reserves the right to reject any application due to any one or a combination ofthe following:• False, incomplete or insufficient application information;• Credit score 550 or less,• Credit showing delinquent accounts with collection balances due; foreclosures, bankruptcies, liens againstthe applicant for taxes or child support, judgments against the applicant for evictions or property damage;• Rental histories showing excessive late payment, NSF checks, property damage, lease violations;• Income shortages less than the required monthly amount;• Criminal histories showing felonies, misdemeanors, DWIs, DUIs, theft by check, domestic violenceHaving something like this will help you eliminate "gut feeling" criteria and ensure you are treating all to the same standards of qualification. 

I just have to treat this as a long term investment and expect to flip a few units at the onset.

As mentioned above, there are state laws that are very specific in how to treat tenant's property.

hahaSo now that I have that loan on the books, I'm trying to find a way to keep it and not sink $35k into paying it off, when that $35k can go into a rental property or a note etc.On that note, @Chris Mason, how does income from a performing note get treated for DTI purposes?

But I'm not really even considering trying to find a different realtor - the one I know is really good at her job and treats us fantastic, so we're sticking with her.

But keep the expectations clear and treat it the same as you normally would.

Expecting tenants to treat the home like you would is not reality.