Since your lot is already zoned RS3, you can (by right) build a new SFH or 2-flat.

Inspections are more frequent. 

I'd do what you can to keep yourself uninvolved with it....but still help your Grandma of course..A trip to the City (Planning/Zoning/Building Depts) will give you some valuable info.

Go to BUILD YOUR TEAM at the top of the screen and look for local investors or meetups in your area.

I studied RE development and investment for my MBA, I am the building inspector for the town where I live and I worked as a contractor before switching to only working on my own deals.

Are there any similar surrounding buildings?

Or, should I focus on just holding these forever type deal and build a cashflow monster? 

I has two GREAT property managers that immediately come to mind, one handling 5 high end high rise condos I owned in Phoenix and the other one handling a 12 unit very lower end apartment building I owned in Arlington, Texas.  

They try to integrate inspections, and the closing docs on their platform and doesn’t work well.

Curious if any General Contractors have recently originated commercial general liability insurance and build units that are sold as Condo/PUD's.