Some more thoughts I have:
The guy that sold me my building was a long time land lord, 100's of commercial and residential units, and one of the last words of advice to me were "high rents are overrated, keep your rents low and get good, long term tenants". Boy was he right. A little old lady at $1,000 per month that stays for 10 years is un-measurably better than a group of 20 something guys at $1,200 per month having parties every night, parking on the lawn, breaking stuff and on and on....
Paying rent late can be a good thing, I had one tenant that paid 3-6 days late every month, and always paid the $50 late fee.
You mentioned smoking, I had two chain smokers in a unit for one year. When they left (stop paying rent and left their junk behind) the walls, ceiling, and mini blinds were coated in a sticky yellow residue. Painting does not cover it up, you have to use special primer to coat over it, then paint. That story reminds me of all the days and nights I spent working 7am - 4:30pm at my day job, then 5pm to 11pm working on the apartment building, then up at 6am to do it all over again.
Both of my posts on this subject have negative tones, however I had some good times too, the money is alright and when I sold the building I got paid for all the work I had done.
