The downstairs tenant is an elderly lady.  

My building is a one month minimum so it's fairly easy to fill with 3 separate tenants, usually elderly couples from Canada, NY tri-state area, and cold midwest states.

I would avoid offering on buildings with elderly or disabled folks. 

One of the particular areas that my partners and I wish to focus on is owner financing and specifically targeting people who own their homes in full or elderly owners who may be looking to avoid capital gains taxes if they were to sell their homes.

Too many of my elders reoccupied their rentals for 2 years at a time and then sold tax free so the irs cracked down on the rest of us. 

If this guy is elderly and/or disabled the court could give him up to a year to move (and maybe even make him pay you "use and occupaancy" while there) also if there are kids still in school they might get to stay until the end of the school year.You want a good eviction attorney on your side who knows how to fight for you.

Most elderly people in that situation like having an income stream to supplement their retirement and is why they still own rental properties and converting from landlord to lien holder would alleviate the hassle of them having to do improvements and repairs, this could also offset some/most capital gains as well.

Just as an aside on how elderly folks think. 

I get that.however talking to a past owner can have benefits. you can learn of defects that you can address in the property.. or in my extreme example of just talking to the lady I turned the tables and made 750k in net profit on one 125k foreclosure.. that certainly would never have happened if I had not taken the time to talk to her and try to help her out of a very miserable situation for her.. keep in mind that was then .. and a lot of people losing homes in those days were older had no jobs.. all they had was equity in the home and the kids would talk them into borrowing against it and then go blow the money.. kind of like elder abuse.. 

However, I recently spoke with a multimillionaire property manager/investor who is doing a deal in California that negatively cash flows 30k a year but the way the purchase contract he has on the property that will be executed upon the dealth of the elderly owners will create around 600-800k in net worth for him and he is paying down the owner carry mortgage by 20k a year (so true net loss is only 10k a year).