The 2-3% points in extra cost are worth it if you plan on using as I described above because the use would be for a few  months at most and due to that short term use you can survive a rate adjustment up.But, if you have no plan to payoff the debt like when using for a down payment on a long term hold why pay the extra cost for flexibility and have the additional risk of the adjustable rate with the amortization looming when you can get a fixed rate second mortgage. 

If for no other reason the more predictable and lower maintenance costs are a huge benefit.  

The borrower gets the benefit of having access to capital fast and the lender gets the benefit of charging a higher interest rate and not having to pay taxes on the profit.

It’s true that many property management companies are now incorporating tenant benefit packages as part of their offerings.

Aside from basic maintenance which is simple work, but hard and monotonous work, and keeping the asset positioned to fulfill it's highest and best use, there's nothing you have to do past a certain point to benefit from market appreciation.

If you have material participation, you can benefit.

OF COURSE the Contractor is going to say you need to tear it all out and rebuild the wall(s)  because that's the absolute easiest solution and adds additional work for him.

Other advice, especially that pertaining to tax benefits, is also highly appreciated!

Now a-lot of times you buy a home from someone with seller financing and they hold the note for 6 months to season it and then sell the note to another investor or a firm and then it will most likely show up on your credit because these are more sophisticated investors.In regards to the benefits of owner financing you won't have to pay closing costs to a bank.

Separately, the benefits and disadvantages of renting to Section 8 is a topic of extended debate on this forum.