People like to use HELOCS especially now, if they have a very low interest rate first position mortgage, in order to tap into that equity without losing the low interest.

So you didn't do anything wrong, you just didn't know.As for alternatives, most counties have an appeals process... but you will likely lose if you go that way.  

There are a few options(1)You can get connected with the larger wholesaler firms in the area (2) go through PCPAO site and skiptrace the buyers of similar properties as yours, (3) hunt down the agents involved in the sale of properties similar to yours or go to local REI meetings and pitch it to the investors there. 

You are correct that this site is primarily for investors and I am one.

If you have high W2 income, the amount your STR makes (or loses) will be peanuts compared to the tax savings.

After the Paradise fire Butte county lose nearly two-thirds of its population.

We do land entitlement so we control all sites and tie them up until zoning is approved. we don't buy land that we can't entitle first

The site is accessible via West Morehead Street, South Clarkson Street, South Cedar Street, and Summit Avenue.

All calculations suggest great investment for 4 bed 3 bath in good school zone, however once the tax estimator goes from $2200 to $9500 due to lose of tax credit from not being a primary residence it hard to see how to get property in SC.

Communicating timelines and expectations upfront can help prevent losing good prospects to other properties.I'd say it's a potential red flag if they want to sign the lease without viewing it.