What question should one of these home owners ask?  

Most of the stuff you can get at Home Depot or Lowes and get it the next day, so no delays once you decide on something. 

If a HELOC isn’t an option, alternatives like a home equity loan, business line of credit, or a DSCR loan could work depending on your situation.

Like any tool, you have to know how to use it correctly or you could get, "injured".We use it to quickly sift through multiple options - and that's about it.BP has a Rental Calculator that includeds everything you are asking about: mortgage P&I, property taqxes, home insurance and percentage for maintenance & vacancy.It also includes Cap-Ex percentage, but in our experience it's a waste of time to worry about this.

Also, the original septic is built for a 2-bedroom/1 bath home, but now the sellers have added another 3 beds and 3 baths.

Sorry, not sure what you mean by pay for her home for 10-20 years?

And if a property is owner occupied, how can you secure a loan with a hard money lender not being able to view the home to estimate repairs?

I was considering staying close to home.

I’ve owned different residential homes in California, both sold off market and for over asking.

Any tips are welcome.