Easiest way to look at this generically would be:Proposed mortgage payments + any other monthly payment you haveYour monthly income + 75%*long-term rentsThis always needs to be less than 50%, and of course other factors would influence your ability to qualify but this hopefully will give you a way to guesstimate the feasibility. 

This also serves another purpose, banks require a PSF to approve you for commercial loans hence having this document completed aids in your ability to be approved for loans promptly.

I'm capped on time and physical ability to do everything myself though. 

With rental properties (assuming your using leverage), you receive the benefits of increasing equity (forced savings via mortgage reduction), ability to lend against the asset, tax benefits, depreciation, cash flow, and possible appreciation to name a few. 

Those who have yet to buy a home (millennials and younger) are going to get completely screwed and have little to no ability to build wealth on their own through real estate due to cost of housing compared to incomes and the only way they will be able to do it is from mommy and daddy hopefully having significant equity in their home.

This may affect your ability to get credit.

You're ability to manage is what will make or break this.

Taking way your ability to contact the tenant eliminates your ability to keep the PM honest.

In Chapter 9: The Multifamily Millionaire Model, Turner explains how you can use the cap rate formula to increase your ability to make wealth.

With that being said anytime I was not doing class work and studying I was taking the time and reading about all things real estate and this past Saturday I learned about wholesales and was very interested so when I got home Sunday I spent the entire day learning about all things wholesale and was actually very confident in my ability to do this.