What do you think would happen if the tenant burned down the property and your insurance came to find out you were not registered as a rental and didn't have the city required smoke detectors. 

Our last crazy obnoxious tenants (told my hubby he was "racist" coz he asked both Caucasian husband and Asian wife if they smoked dope; turns out she did, vs. our policy of no smoking!)

Its more important to have the intent correct: ie 'no burning of any substance' to cover smoking then not to have any mention.

I prefer to have a non-smoking building.

Purchase the property from your example and now monthly debt increases to 2.9k and monthly income increases to 5.9k, new DTI=49%I believe to do this strategy numerous times you would a.) need to get smoking deals or b.)have a high monthly income 

It contains the most important forms: application form, lease, ruels and regulations, lead disclosure, smoke detector and CO2 notice,  pet agreement, non standard rules (lawn and snow etc), 5 day notice and folders. 

I would verify the rent rate and your exclusions first  (Smoking, pets, etc).

The tenant is incredibly difficult to deal with as she smokes in the home, doesn’t pick up after the dogs, doesn’t maintain the property, and rarely pay rent on time.

Would I be able to paint the ceiling with dewaxed shellac to cover the smoke stain ,(and smell) without cleaning?

Even if they swear they'll never smoke inside, they will, and will drive your other tenants nuts and it's expensive to get the odor out.Get your tenants to pay online so you aren't chasing the rent check.Be direct with tenants.