If you own either of the properties free and clear and don't need to access all of the equity to make the next purchase happen, that would be ideal.

Tools like Zillow, Redfin, or even MLS data (if you have access) can help.Good Luck!

Validate planning zoning requirements and access to utilities.

You could ask that they put a year or so of savings into a separate account on which you have view access or receive a monthly statement so you can see they have the ability to pay future rent.They aren't going to last without other income or savings with income at 1.25x rent.

Imagine a real crisis where they couldn't get the grid back up, and you couldn't access your accounts, etc.  

The course heavily relies on cold calling and emailing, which hasn't been effective for me as a novice.I'm considering a different approach, such as arbitrage, as it seems more accessible for a beginner.

You should not have allowed access and now you are going to live the old adage of "it's easier to give slack later than to real it in." 

Even though there is a tenant there now, the association could restrict or limit renters there.

However, in the event of an emergency, the Landlord and/or his agent has unrestricted access to the property.

If I was the originator on this loan (loan officer, lender, or whatever title is used), I would have made this restriction very clear to my borrower if they had explained that they wanted to eventually use the property as a rental.