I became a landlord out of necessity, but I realized two things. 

It’s a very lucrative companion business to my real estate investing.Houses are considered a basic necessity of life.

I have major categories that are necessities, leisure, work, and then sub categories like eating, sleeping, social media, house searching etc.

This is a really vague question...A wholesaler in general is a necessity to markets.  

I still live at home and it's not a necessity for me to move out yet, and I plan on making a steady stream of income from this property ($1500 a month).

Here in Sydney it's not such a necessity as roofs are either terracotta tiles or metal and they get replaced maybe once in a lifetime (local metal roof manufacturer gives 30 years warranty).

So I almost thinks it's a necessity for my work to be able to talk all of them.

I personally downloaded a standard lease that was designed for my state and then I went through countless webpages outlining the "necessities" for a lease.

I would never rent to the first applicant because they qualify since there may be many more applicants who are more-qualified.Other than the necessity for an applicant to have a history of having adequate cash on-hand to cover their rent and other expenses, some of the most-important factors I consider are the things that tell me whether or not the applicant will keep the place clean, be free of mentally aggravating issues, etc..Here is an example.

Min $4000 (basic necessities), comfortably (for us), $6000.