This structure allows you to form a corporation and make your retirement plan a shareholder.  

How does the structure of private lending work exactly?

This will restore the structural integrity and give you a smooth finish.

At that point you've structured the transaction so she avoids SE tax. 

Before anyone suggests building a home or putting a mobile on it, I am aware of that option but this post is specifically to ask about your opinion on putting storage units on these empty lots.Please consider that these are 'average' areas so a sheet metal structure with a chainlink fence around would be out of the question.

The virtue of the TIC structure is that they own a piece of real estate independent of you - it just happens to be a smaller property that is a % of a larger property that you also own some of. 

No.If you are the sole owner of the holding LLC, and the holding LLC is the sole owner of the real estate LLC and trading LLC, there is zero tax difference between a brokerage in your name vs this structure. 

Hello, I have a few investment properties in Sacramento, some other businesses, etc. and wanted to setup  a simple structure for asset protection.

I use a small community bank and credit union for most of my SFR deals I've done because they are able to be more flexible in their lending structures than, say, Bank of America. 

There are a variety of different ways to do this; whether that be pursuing properties in need of extensive renovation and likely requiring cash to close, targeting properties with certain zoning that allows you to split the lot/add additional structures,  etc.