In this case, since they are borrowing their payments, these would get added to the principal balance each month, and interest would be calculated on that.If, for example, the interest rate on the note were 10%, they would implicitly be borrowing their payments at that rate.

Sounds like you're asking for a private lender to go into second position to convert equity into cash behind an existing loan on these properties. 

Not worth it on a 100k house, probably worth it on a 300k+ house in the long run. 

Here's some online software options that you commonly see recommended on BiggerPockets.

We have many efficincies under management with a ~10% vacancy rate with prices ranging from 485-625 depending on location property quality and amenities.

Usually with an on site maintenance handy man versus the heavy costs of commercial services.  

I am based in Houston and currently embarking on my journey into the world of real estate wholesaling.

Our kids' university has parent groups on Facebook.

As far as home office no longer being an IRS "red flag" I guaranty that if you put a home office deduction on a personal return on Turbo Tax it will move their audit risk needle.

Any advice on what setup is easiest and most tax advantaged?