Our initial plan is to house hack a quadplex somewhere in Orange County.

In this manual (which I assume could be modified to provide to tenants) I include all the financing information (which you would not include for tenants) bank accounts, mortgage accounts, payment information, and mortgage payoff), a list of the contractors, what each contractor does, a list of upcoming planned or necessary repairs, and a copy of all leases associated with the property.

I'm looking to having my mortgages paid off as I plan on early retirement and the rentals are part of my retirement income.  

He knows we plan on continuing to grow our portfolio.

I will suggest you plan to House Hack a Duplex or Triplex or Fourplex every year for the next 4 to 5 years and you will thank me later.Goodluck man and keep us posted on your progress!

Should I spend money on professional photos?

Little to no rehab/capex spending was needed.

Who wants to spend $100 to view a rental?

A good real estate accountant can save you thousands of dollars by leveraging entity selection and formation, tax deductions, cost segregations, bonus depreciation and tax planning.I recommend finding an accountant who specializes in real estate taxation, business taxation, financial planning and tax planning.You may want to consider working with your accountant remotely to expand your options.I would also recommend looking for a accountant willing to work with you throughout the year.

If you plan to resell, I think it's wise to discuss with seller in advance and that way the lien on the property can be transferred to second buyer, but you can continue to make payments at the former schedule etc.