That means that whatever the sum of the Principal + Interest + Monthly Taxes + Monthly Insurance comes out to be, as long as the rental income exceeds that then it will qualify.

Insurance, tax, tenant info, leases, applications, listing/marketing docs, water, notices, repairs, logs of maintenance and tenant damage, etc.

I’m 21, and after taxes and all expenses I have $55,000/ year I’m able to invest.

Insurance companies often obtain the floor area from the tax assessor and base their coverage on that, @Ryan Fox. 

Since he’s 62 I know we can withdraw with no penalty, but is there a way to avoid taxes ?

I can’t help but think I’m running out of my youth to do physically taxing things.

The laws also make you register and pay hotel occupancy taxes, with some serious penalties if you try to not do either.Also, Airbnb doesn't work everywhere here.

DSCR loans are underwritten based on your credit, liquidity, and the rent you will receive vs the principal, interest taxes, and insurance.

You're completely deferring all tax on gain. 

@Tammy Muller here are two great threads that cover the accounting software options and feedback thoroughly: BP -> Quickbooks or something elseBP -> Fav bookkeeping/accounting softwareThey don't mention either of these options, but that might be because RentalHero &  REI Hub are full-blown property management software, and Quickbooks Online, Digb, and Stessa are accounting/tax software focused on real estate investors.