Lower Start-Up CostsTraditional real estate investing requires 20%-25% down, making it difficult for many to scale quickly.

They failed to rent a unit in a great location/condition and a hot market for 4 months, and the rehab expense reports don't line up with the estimates they provided.

Are we required to pay FICA tax on the deferred income? 

If one partner unconditionally guarantees the debt, this can sometimes require some side room guarantees to that partner to ensure no one recognizes a capital gain.As a few others have alluded to, there is a secondary problem known as a "debt financed distribution interest expense." 

We require them for any tenant over 18 years old.

And this might indeed require some time to pass before doing that.You could still create a single member LLC with either you or your wife as member. 

To permanently affix a mobile home to the ground requires a foundation - just “tying” it down doesn’t qualify.  

And the housing stock in Miami is older and so much more expensive for what you get in comparison to new construction in Cape Coral.

In larger multifamily investing it's about finding opportunities to increase revenue and/or decrease expenses to drive value.

400k is so expensive for such a small home.