This is a great place to learn and to connect with people so take advantage of all the great resources.

There is too much to learn at once. 

With 20 years experience managing my sfr and as a property manager for a broker and a bank, this switch into ABNB has been a learning experience.  

Flipping homes in San Diego has been an incredible journey, and over the years, we’ve learned a lot about what works—and what doesn’t—in this market.

I think you're confusing the quantity of items with curb appeal.

Although the list may seem intensive, I look at it like this: The total cost of all these items can be much lower than the cost to repair a hidden surprise after purchasing a property to flip. 

Given the scope of your work, a simple plumbing leak would not concern me, it's a $200 issue at the most and ideally, it's just another line item when you do rough in plumbing for the kitchen.Being in a Milwaukee suburb, I am guessing it's a 1960s ranch, probably with galvanized plumbing.

Have an itemized   Otherwise your bill will go out of control and you won’t know why. 

Due to item 1, adding an ADU can require years to start achieving any return (once the accumulated cash flow recovers the initial negative position).4) Adding an ADU is a slow process.

What were the biggest line items?