(Unfortunately, the investor fell for this gimmick and did NOT get their own 3rd party inspections, appraisals or even visit the properties they were buying, against our best efforts to encourage proper due diligence and follow our check list for their own protection.)So now some people are stuck with properties worth half what they paid (not all RWN members), with no renovation done, and constant repairs and vacancies. 

Because it allows you to "harvest" the accumulated gain or loss for tax purposes while still holding the investment.

This gives much better diversification protection across geographies, asset types, strategies, investment subclasses etc. versus putting all the eggs into one basket.The downside is that it's not for everyone, and a person has to be comfortable with turning over control to someone else.

They are the ones protection your investment. 

In these instances typically the lender will pay it to protect their interests. 

The tenants should have renter's insurance to protect you.

Another key benefit is diversification; an SDIRA allows you to include real estate in your portfolio, reducing risk by spreading your investments across different asset types, which isn’t possible with a standard IRA.Moreover, assets in an SDIRA often enjoy protection from creditors, adding a layer of security to your investments.

I'm not into Sub2. there is no personal liability protection in a single member LLC.. there is protection if you have unrelated members in your LLC . 

Maybe they've been burned by landlords in the past and are being very careful.You can legally reject them based on personality, facial tattoos, body odor, or other factors, but you better make sure you can prove that it wasn't based on any protected class like race, religion, familial status, etc.

Also, take as many pictures as possible before the tenant moves in, again this protects you in case of damage caused by tenant.