It's not impossible, but working with family in this way is much more likely to cost you a relationship than make you money.

This will give you the best net. selling with a squatter in place is not the best move and will eat into your profits as potential buyers don't want to deal with remove the person and gaining access to the property will be impossible. 

In a lot of markets it’s nearly impossible to hit, and if you sit around waiting for a textbook 1% property, you may be sitting on the sidelines for a long time.

Not impossible...maybe some people want that MIL or ADU or office/studio, etc at home, but that is a smaller pool than general public. 

The bummer is I’m in Fresno Ca housing cost is high, rents are low, insurance sometimes can be impossible to even purchase.

I would not say this is luck because it would be hard, if not impossible, to consistently repeat. 

Tax deductions for the business portion will work almost exactly the same as if it was a separate building.The exact way rental property taxes work is impossible to describe in one post.

Inventory is tight, and demand remains high, which makes single-family homes nearly impossible to cash flow unless you’re bringing a large down payment or looking long-term or perhaps even Airbnb.

Cause if they don't then I'll have to resell the land, which we all know is next to impossible to do unless it's located perfectly. 

We spend thousands of dollars per month on fraud detection systems and they are virtually impossible to catch without them.