Yes they are supposed have endless hot water but they can only heat it so fast and a smaller unit will not keep up with a shower and the clothes or dish washer.One of the biggest problems for tankless water heaters is improper installation especially for natural gas versions.

Someone that makes 3x the rent, and meets all criterias is likely going to keep there job, or atleast be able to weather their own storm.I think tenants that make 3 X to qualify for a 700 dollar renter will not have reserves.. tahts 2100 a month before tax's subtract 700 for rent  150 for utls.. etc that leaves them maybe 1k a month to buy food cloths insurance car if they have it etc..

They wore fancy jewelry and clothing worth more than my rent. 

We also have local charities that help underprivileged children with food and clothing.

The tenant would always put her clothes in the laundry for more than 3 days straight every time and don't take her close out from the laundry!

Disposable income is very alluring, you can get new clothes, get a new phone, buy stuff for your hobbies.

Even if there is a little smoke smell left when you are finished, they won't notice over the cigarette smell on their clothes.

I'll simply say that in my opinion, there is a vast difference between "gurus" (the emperor has no clothes) and real educators (teachers).

Clothes galore. 

You are no different than a store selling clothes or other items/manufactured goods.