Most are investing in apartment and larger projects or blended offerings that have 2-3 year returns, and have lower risk.The question about the $100 was in regards to risk, not what the return was.  

Looking to the near and mid future I see interest rates going up which should have a negative effect on real estate prices, as investors that don't want to be in real estate can invest in something more liquid bonds etc.  

I got larger credit lines, better promotional offers and incentives.

It only creates liquidity and effects the amount you have to pay back.  

@Paul Kessenich- in Nashville, the target market for these larger home is bachelor/bachelorette parties and other larger social functions (reunions, weddings)That is another degree of risk for long term.

No liquidity—A few sites are building out secondary trading platforms, but I’m not optimistic that you will see a lot of trading of interests on them.

3) If we decide to liquidate the house in 15 years, am I entitled to more of than 1/4 of the profit? 

Yep, there are more volume guys now, doing 10-20 flips a year and they are willing to work on lower margins but doing a larger volume.

In order to get a loan to do this (since I am self employed) we may need to go with a private lender as opposed to a conventional mortgage, so we would need a larger down payment.

Larger brokerages, 2,000 to 3,000+ don't let new agents on the street without agent training in-house.