This would not be your own home anymore, so don't fall in love with the property. 

At the very least, you need builder's risk, fire, and liability coverage.What's your plan if someone slips and falls on the site, or if someone breaks in and damages/takes materials or tools, etc? 

My suggestion - better in time and effort, and money (through the mistakes you going to make), than paying a guru.Between BP and books and all the other podcasts and blogs available for free, you shouldn't need any paid training - don't fall for that.

I hope you looked at an actual flood zone map and ruled that the property doesn’t fall within a 100 year flood zone.

Savvy real estate investors do this too - buy property when it falls through the floor, accumulate cash when prices are high. 

If they did, they would probably fall into acting as an agent for the seller and they likely aren't licensed and don't have a listing agreement to allow them to do that.

The joint venture side of things is treacherous as that's what many people do to avoid falling under the purview of the SEC, but an SEC attorney will tell you not to.

His side is gutted, neglected, and quickly falling into disrepair.Regarding the roof issue we have consulted a lawyer who says not much can be done to “force him” to repair the roof.

You would think they would be falling over backwards to assist, considering this increases the likelihood that the delinquent taxes would be brought to current. 

We recently had to do exactly this, due to our contractor falling ill.