I do not know California law but it is unlikely that it was illegal to take the loan from your family member;  however, you left your family member in a very vulnerable position.

I feel as if this could be a low risk opportunity to get my feet wet in the business without putting myself in such financial vulnerability.

Clearly defrauding someone would be out of the scope of this thread, as we are talking about people running real business without the intent to defraud people, which is the main avenue to pierce a vail in the court systems today.The most common factors that courts consider in determining whether to pierce the corporate veil are:whether the corporation or LLC engaged in fraudulent behaviorwhether the corporation or LLC failed to follow corporate formalitieswhether the corporation or LLC was inadequately capitalized (if the corporation never had enough funds to operate, it was not really a separate entity that could stand on its own), andwhether one person or a small group of closely related people were in complete control of the corporation or LLC.Some corporations and LLCs are especially vulnerable when these factors are considered, simply because of their size and business practices.

Perhaps a solution to solve the concern about the landlord’s vulnerability is for him/her to do business as an LLC.  

His rationale in requiring more security is that the value of a storage facility is so heavily based on income and banks are known to run them into the ground during and after foreclosure so his second position would become vulnerable--not that either of us actually anticipate a foreclosure.

A refinish is just a stop gap and only makes the tub more vulnerable to damage in the future.

I feel somewhat vulnerable, as it is a new area for me.  

When properties become free and clear they become more vulnerable to lawsuits, so as a precaution, and especially because you already have one setup, I'd move those to the LLC.

Full disclosure, some people really don't like signs and in some areas you might even be vulnerable to fines.

One thing about being on the Internet makes you more vulnerable to the mind of competition and makes the things you say can help other people.