I am not sure what type of real estate investing you're considering, but it sounds like, with your family and busy job, you won't have a lot of time to be hands-on or personally involved. 

Only large corporations can withstand this kind of risk.

That better life podcast has taught me that there are a lot of ways to get involved in investing.

Leverage magnifies return. 3) The effort involved in adding an ADU is comparable or larger than a rehab associated with a BRRRR.

In that case you should get an attorney involved as encroachment would be a material issue that if known should have been disclosed both to the broker and to any potential buyer.  

While both involve finding and properly securing a site and bringing it to full entitlement, the ground-up process includes the land piece but gets way more involved and complex to execute.The full "Monty" for ground-up development needs to include financial literacy, an explanation of metrics, and how they work.

So there is huge risk expecting the 15 year limit to be reality.  

There is risk with this approach that the tenant can have short residence or leave in Nov to January.  

Probably the hardest thing some of us ever do is give ourselves permission to risk failure to succeed. 

We've never actually had a tenant use it after reading the addendum (which was our goal), and I think it helps prevent problems when they understand the myriad issues involved in its use.