And most of BP isn't a huge fan of buying into equity essentially. 

This would essentially be a purchase and loan agreement where the current owner acts as the lender and you as the borrower.

Essentially the BRRRR strategy.

I have about 4 years left on the 5 year term and I've run the numbers which shows if I can buyout the mortgage, it would be profitable to pay the buyout penalty fees.Is there any way that I would be able to renegotiate the existing mortgage rate with my current bank or would another bank be willing to essentially "buy out" this mortgage and win my business by replacing it with a lower interest rate mortgage?

Yes, essentially and Ideally iwould be living In one of the units. 

The utilities aren't essentially in their name. 

This will help cut your learning curve down, essentially getting free mentorship from someone, if you were to bring them into the deal, even if you have to give up a big chunk of the pie)

I still saved $2800/year on mortgage interest, but I didn't pay any interest for the $73,000 - in fact, they essentially paid me $2200/year or 3%/year to use their money.

The housing provider may not ask for access to medical records or unreasonably delay the request.Note I specifically highlight TREATING therapist, some online site is not a treating therapist, even it a licensed therapist is what they use to essentially scamp the system.I also don't see anything about not charging them an additional fee, just can't deny them, nor do I see anything about requiring them to add the animal as a rider on their renters insurance. 

Pre -approval is essential to have an agent take you seriously.