Stated another way, give them enough info to warrant further investigation into the matter, and leave out enough details to make them want to call you back.

or the IRS decides to investigate me, or....., or...., I think it'll be hidden somewhere that only I know about.

The thing about it is that they choose to investigate, prove it and then prosecute.

I'm neither, but having investigated this same topic recently, I can at least give you a couple of clues.I believe the federal gift tax and estate tax are now unified, so gifts during your lifetime do eat into your estate tax allowance.

I'm thinking duplexes and am still investigating hard money.

You say it isn't a great way to raise capital, but if you aren't out of pocket for living expenses, seems to me you are building capital.Have you investigated using a FHA 203k loan?

Both properties are Class 02.Property 1) Residential with a mobile home on the lot which is occupied by (according to my research and investigating) the previous owners daughter and husband.Property 2) Completely wooded lot previously owned by a homeowners association.

Investigate the rules. 

I disclose what I know and I have no obligation to investigate further doing the due diligence for a buyer.The inspector/contractor is an extension of the buyer, the buyer is his client, I'm not his.What ever a buyer claims to be faulty or in need of repair is NOT knowledge gained as an owner or really known by me.

You have properties and record owner names but need to skip trace to locate.1) Free online resources: try searching owner by name in Google, etc.2) Social networks - try FACEBOOK others.3) Interview subject oroperty neighbors4) Paid and Subscription based skip trace apps5) Paid skip trace locating services and licensed private investigators