As far as any specific requirement on California I would need to do some research for that.  

This normally would not be an issue but the cost of the water/sewer is extremely high in this area and specifically because the meter is a one inch, the costs are much higher than a normal 3/4 inch on a non-duplex. 

Looking for suggestions on any specific building materials, fixtures, accessories, furniture, and tech for a STR.  

Would also love to connect with experienced Cleveland rental investors.Much ThanksCleveland, Ohio is a great market to focus on for cash flow and specific pockets have gone up 2x and upwards of 4x in the last 5-10 years even!

I get the dreamers wanting to pay to get into development and I can see in some markets this would work were its not so intense to develop but in other markets ( and I am sure the Guru just takes your money and does not get into  market specifics) 99% of the folks buying this will never do  anything with it.. it takes decades to figure this out or U need to be with a BIG firm that has millions upon millions behind them..

I didn't want to list this under Scenario 1 as it's redundant and whether or not having more control over your down payment is a pro/con is pretty case-specific.3. ???

I have spreadsheets filled with material lists for every phase of the build that includes pricing for materials as well as labor, and sources that I use for them.

Cash flow has been hampered by an increase in cost of ownership recently, specifically insurance. 

Nore the rent control bullet is CA specific and I do not know how ADUs affect rent control in other jurisdictions. 

Did USAA give you a specific list of renovations they want done?