If you wait a few years after your official retirement age then you can get a multiplier of up to 1.3x your base.

If you buy using hard money, and it's officially recorded with the county as a mortgage, you can start the process of rate/term refinance out of the hard money the day after closing using plain boring 30 year fixed Fannie financing (at least I can, I can't speak for what other lenders do).

Now, I am just going to become a real estate investor through the proper channels by obtaining my license and acquiring as much knowledge as possible, seeking advice from peers, and putting into practice in what I've learned.

Hi BP,I've read a few posts and googled and based on my previously paid off properties I now wonder if I'm missing necessary documents (note) from the lender.Another property that will come up for being paid off so I want to understand 1st do I need to go back to the lenders and request an official document be sent to me and what to be prepared for with the upcoming one when the dust settles.By definition I know that I sign 2 documents at closing, mortgage or deed of trust and the "note" that I promise to pay.I paid off the "note" on 2 previous properties and what I have in my records are copies of the "satisfaction of mortgage" or "release of lien" of the mortgage.

Account Closed Official Public Records of your county. 

What does the building official have to say?  

Unfortunately, there is no way of knowing for sure unless you own the property or have done enough work in a particular town where you know how building officials react to a particular situation.

There are 77 official neighborhoods, but a ton of sub neighborhoods too.  

If it explicitly reverts to month to month you can cash the check and give them an official 30 days notice to leave  unless they sign.

Based on all that, you now have a full game plan that is repeatable and workable to get you to the point to replace the income with passive income and then officially retire in comfort, maybe even sooner than you thought.