@Sean OvercrestThe transaction that you've proposed has several different tax implications: income tax, gift tax, estate tax, and yes, property tax. 

Buying a mobile home to place on your land can be a great way to generate rental income, but like any investment, it comes with pros, cons, and key considerations.On the pro side, mobile homes are typically more affordable than traditional single-family homes, meaning lower upfront costs.

Though it may cash flow well based on their current debt service, when you compare the income it produces to the equity they have is it actually even a good investment for them from an ROI perspective or would they be better off liquidating and redeploying?

You can purchase a primary home with seller financing, then rent out the spare rooms to generate income.

Today I have 48 homes but starting to reduce my portfolio in some areas and looking for completely passive income streams. 

It doesn't book as frequently as the smaller house, but generates more income.

A year ago, my taxes were pretty straightforward—just W-2 income and some Airbnb earnings from my place.

For example, I mention that every adult must pay a $XX application fee, pass my credit/criminal background, make a combined income of 3x the rent, and whether or not the property accepts pets.

When you say "section 8" tenants, are you looking at low-income housing tax credit type properties, or standard rentals that are in lower income areas and therefore cater to HCV tenants?  

Why would you take your cash, and spend it on a property you don't need to spend it on, instead of using that cash to increase your properties,...and income.