Is my accountant accurate in stating I cannot deduct the expenses related to the property if it's not listed in an LLC?

Like websites or anything that gives accurate information. 

As far as gathering SSN, there are skip trace services you can look into.

Besides putting together the best SOW using accurate/actual quotes as @Peter Mckernan and @Alan Asriants commented above, another key aspect is tracking expenses (bookkeeping) and monitoring the budget throughout the project. 

Furthermore, if anyone knows of a third party that provides the data or is interested in periodically gathering the data for me from the county courthouse (for a monetary reward), please reach out.

If that leads to a more structured and education based meeting, then that is great - if it remains just a place to gather and bounce ideas and network, that's great too.

Nowadays, people can make paycheck stubs/W2's that look convincing so just make sure you invest in software that gathers verified information on applicants.  

Connecting with local contractors or experienced investors in your area is also very helpful for getting accurate numbers.For ARV you’ll want to look at comps; You can start on Zillow or Realtor.com but I highly suggest connecting with a local agent.

Underwriting a new construction is like a flip on steroids in terms of volume, however you will find that you can get a much more accurate budget in the end because unlike a flip, there are very few unknowns going into it.

I’ve been dreaming the last few years of starting an event venue, something for weddings, gatherings, etc., preferably with a great outdoor space.