Sounds like a great learning experience, as well as practice exercising that risk muscle. 

I live just south of Atlanta, GA, have a lovely wife and I enjoy playing music (guitar, piano), exercise and trivia night at the local pub.Feel free to reach out to me. 

However, it is very rare for a bank to exercise this clause and call the loan due.

Just start going to seminars on topics you want to learn more about, events that look intriguing, etc. but exercise some discretion especially when they are charging money. 

You will now have a huge monthly bill that you must pay.I'm not going to tell you how to think, but looking at mortgage loans and comparing how much you pay in interest is not a beneficial exercise IMO. 

Question: If I have the borrower's sign a deed-in-lieu before closing the loan, what would trigger my ability to exercise it?

Get a sizeable option fee (make sure the option states it's non-refundable option fee or the like) that you can keep regardless of whether the option is exercised. 

Basically these are exercises for me at the moment as I begin to understand how the numbers work together and against each other.

@Yana Sha You aren't going to get anything of value out of this exercise without posting the property location.

A properly set-up DST will both protect your assets and bypass the burdensome franchise tax that would be levied against a Series LLC.The Delaware Act expressly provides that “[n]o creditor of the beneficial owner shall have any right to obtain possession of, or otherwise exercise legal or equitable remedies with respect to, the property of the statutory trust.” 12 Del.