We both have stable income from full-time jobs (2+ years). 

There is zero proof that card systems work better, generate more income or make life any easier.

Market Data- I like to personally look for top employers in that market & how many employees they have, look at trailing population growth and the direction it has gone, the population itself if it is an tertiary market, job growth, median area income, etc.

Add taxes and insurance and you're looking at closer to $3,000 a month.

(Fannie-Freddie just started allowing projected income from ADUs to be counted toward qualification this year.)Just in general, though, any kind of rent appraisal I see here in Colorado -- be it for short-term rentals/Airbnb or for LTR -- are woefully low. 

A lot of areas are cracking down on STR and/or charging fees (taxes) to run one.

Nevada is a landlord friendly state, 4th lowest property taxes, no state income tax, limited housing supply with tech and manufacturing jobs moving to the area from CA.

Knowing things like median income for an area,  median rent , population growth, unemployment and investment of companies are some information that id like to research.  

I'm not ruling out Florida, but it isn't my focus because of taxes and insurance costs.

There are no taxes or penalties for taking the loan so long as it is paid off according to the terms of the loan policy, but you will be replacing that once pre-tax money with after tax money.