I'm a real estate investor based out of the Myrtle Beach area.

You will be able to see the numbers based on some assumptions.

You have to evaluate based on market, but there are other means of achieving forced appreciate that might make more sense. 

I currently live in Charleston and am a fishing guide by trade so I have a good base understanding of how water moves through salt marsh areas, but it'd make me feel a lot better about this purchase if I could have an expert look at it.

Based on my experience builders make a lot of mistakes during construction.

4) any Charlotte based resources that come recommended to help me structure this properly?

Always weigh the pros and cons of each option based on your financial goals and circumstances.

Based on your description of the situation, you're not going to cashflow while you live there, but the question you should really ask is, will it cashflow after you move out? 

(And it seems there's at least some chance it doesn't pass at all, based on the opposition they're setting.)

Other than Mashvisor, are there any other tools that can automatically filter out any new MLS listing based on my criteria (e.g rent avg, cap rate, expense)?