More than likely, you will need to meet ingress and egress requirements - Illegal renting is tempting, but practically suicide.

This implies residential units can be built at lower costs and provide better return. 11) adding an ADU to SFH can make the SFH fall under rent control.  

I would like to avoid providing keys to the tenants and just have them setup and control the codes for access.

I'm looking for any / all advice for best practices around how and when to inform tenants about the rental increase/request to vacate.

I know many are passionate about the real estate practice, I acknowledge that and am knocking it! 

Splitting services is definitely ideal, but not always possible or practical.  

Definitely encourage you to practice analyzing a few properties using the “Deal Finder” at the top of your screen, and the Calculators (Under “Analyze Deals). 

However, in practice, holding the replacement property for at least one to two years is often recommended.

Nobody really knows how low they'll go but I agree with predictions of 20-25%...and I wonder what Agents are doing to make up that delta in their revenue.We diversified well in advance knowing we needed to create additional streams of income, ideally by simply focusing on what we control, the size of our roster, and more effectively monetizing all of our current transactions. 

Another strategy is to work with the heirs in order to control the deal.