For example, what is the required income to rent ratio, amount of time spent at current employer, credit score, etc etc.

Catch is ... it is zoned at RM20-A, which for those of you keeping score at home, is apparently not eligible for a Non owner occupied STR. 

Take stock of your current credit score and accounts.

Going to depend much more on more details / your personal situation - all things equal you will probably get better rate/terms on conventional if you qualify for bothThanks I have a good credit score just trying to get rid of that PMI 

I had a whole Analysis typed out but my wifi cut out so I've retyped a summed up version.

It seems like a beta version of some amateur's app.

I am very disappointed that I am not longer able to perform tHe tasks I have been able to do unless I pay twice as much as paying before for their premium version, which is now from 13.99 to 23.99The price change seems unreasonable, so I will switch back to use the bigger pockets tools, which price is more reasonable.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

I require a high credit score 680+ and two prior landlord references.

Private lenders tend to focus more on the value of the asset or project rather than your credit score or financial history.