Just like any flip story, my first flip expenses almost doubled (different story for another day 😊), so we are being cautious with any additional expenses.

To me that expense would negate the increased profits of STR, which is the whole point of STR. 

The California Apartment Association (CAA) is urging Governor Gavin Newsom to veto AB 2684, a bill that could lead to expensive air conditioning mandates for rental properties.

Otherwise you're merely adding unnecessary operational expenses.

The vision is becoming a reality but I am still at the planning phase and analyzing deals to ensure the numbers added up after all expenses is my culprit right now...

Same goes for number of LLCs and what to fund them with, since bear in mind that CA tends to be more cumbersome and expensive to have LLCs than other states.California is generally more cumbersome than other states when it comes to taxes and filings.

I am thinking of house hacking through the use of an ADU since I live in a more expensive area than most.

Criminals and homeless will typically move on to an easier target.It is better to spend $1,000 - $2,000 to properly secure the property than to continually deal with these problems and expenses.

Real estate here is expensive.

I would definitely tailor the worksheet for your own calculations; for example, I added a "capex" percentage to the sheet as part of  expenses I want to account for.