South Carolina being a lien theory state, one would normally have an attorney draft a mortgage (which creates a lien on the property and makes the full balance due upon sale) and promissory note (which outlines the payment terms, interest, etc).

It probably takes unlicensed or underwualified workers if they are getting pricing less than half of what the "normal" is.

Someone bails, and we're out a month of rent and a few hundred in make ready but we have 1-1.5x months as a deposit so we're normally good and move into the next tenant. 

As a licensed CA agent, the Seller probably has a duty to disclose that they are a licensed agent.You didn't know they were an agent when you submitted your offer, so you didn't include it in your offer.In their counteroffer, they are adding a disclosure into the agreement that they are an agent, as they are presumably required to do by the state of California.While I don't know the whole circumstances, nor am I licensed in California, that seems fairly normal to me.

Sounds like this is your normal part of education in the school of hard knocks....if it wasn't this, it would have been something else.

I have one in my primary residence as well, but it is used as well as a normal system.

I'm from Cincinnati and we make several trips a year down there and we normally stay at a B&B, but would love to use a VRBO / AirBNB. 

Buyers and sellers creating a market that just grows at a normal pace. 

I rent to people that normally would stay in a motel for a month or two. 

I normally rent to students so I usually find the tenants.