This answer should continue to drive your choices as you invest.

If you do, and it doesn't specify that it's only if they find you the deal, then legally, you have no choice but to use them for the purchase.

It really depends on the individual property.

You find out that this individual, or perhaps both, used to be drug users.

Are you looking around for a networking group to learn more about investing in real estate or are you looking for an actual mastermind group made up of high net worth individuals (most likely millionaires or more) who meet to talk about the economy and their tstrengths and threats to their businesses and how they plan to address those threats as they continue to grow.

What I might do is follow up with people individually if they express interest, find out what their goals are, etc, before getting into the details. 

Realtors friendly individuals?

Each of these variables will dramatically change the advice I give the individual asking me this question. 

It is my choice to have it that way, not the government's.My two cents. 

They tent to limit your investment choices to conventional investments such as stocks and mutual funds.To set up a self-directed Solo 401k you need a specialty provider firm, there are several of us who actively participate on this forum and can help you.