For example has anyone ever added a professionally paved fire pit?

Stephanie Bureau yes that is possible if you can find a tenant willing to risk the short term nature of the initial lease.One case where it might work is employment related rentals.

I'm an employed, high income earner, looking at buy and hold real-estate as a means to diversify my investments and generate passive income.  

In fact, while the number of people employed declined in Dallas in September, 14,300 new jobs were created in Indianapolis.

Residents are employed and working.

Convincing them living in Detroit is a better option than living in Fraser, Westland, Auburn Hills.People are going to switch employers every 2-3 years in todays economy so distance to work matters.  

One more random question: Do lenders generally call employers?

I live in CT where some large employers are moving out and the population is decreasing.

There I learned the town required the new strip owners to add more parking by paving over an empty lot, part of the property not paved.

I am self employed and earn a fair portion of my income in USD, so the conversion rate isn't quite as much of an issue for me as for some.