The main thing I see when coming across this is deferred maintenance.

Hard Money or DSCR is the way you want to go.Shouldn't be an issue where you are as long as your intention is for investment purposes and have the capital to put down.

We have our main monthly meeting on the 2nd Tuesday.

Non-passive to achieve this level of return.Add the addition of the ADU makes the main unit rent controlled if over 15 years old.the work to add an ADU likely exceeds the effort of a brrrr that can achieve infinite return  Experienced investors are adding multiple ADUs by leveraging items like bonus density, committing units to affordable housing, etc.  

It has to be an addition.I would double check because maybe the workaround is reinforcing the garage and building above it.We lived in our studio ADU for two years before we moved into the main house.Best thing to do is talk to an experienced lender.

Would you personally intentionally go out and do this?  

What are the main reasons condos are considered vastly inferior?

But when we are done it’s going to look sleek and intentional.

The intention is good and there can be some solid advice. 

Main problem is that I wouldn't be able to get out there after every visit to clean and check up.