You mentioned that you would have 10k left over in your savings account.

In my comment, I think my point got taken that I spend so much that I don’t have anything left over.

If everything else looks really good and they seem like good renters all around besides the smoking, you could add an addendum into the lease stating that they must smoke outside of the property and that they would be responsible for any damage (discoloration, smells) left over as a result of the smoking.

I need something where I can document all of the on-paper reservations, and still manage to market the leftover nights (as few as there may be) on AirBnB/HomeAway. 

I was young and had no clue . ( to a degree)  BUT the tenant was making my payment and the left over covered some repairs .

In the end, I'd suggest paying the minimum on your mortgage and investing what you have left over in an S&P 500 fund (or something of the like). 

The cash flow left over after reserves, my mortgage, and other expenses is the cash flow that I "pay" myself / my business. 

Every two years, these leftovers are then auctioned off at something called a scavenger sale. 

I also have enough leftover quartz material to do my adu counters for $0, due to it already have been expensed on a previous project.

If you are OK not leaving the balance left over to your family, This is a very good tax efficient option that can aid a cause you care about.