The vacation side is more of a business and requires a lot more work but the affordable housing side is less labor intensive. 

I do it myself and takes 20 to 30 minutes a month (did it yesterday for Dec), with about 7 of those minutes for 1 property in Blount County, TN which requires the form to be manually filled out, write a check, address an envelope, scan doc and check for my records and walk it to my mailbox.

google "all inclusive Deed of Trust" fantastic CA document we used all the way back in the early 80s If I'm not mistaken though a wrap would require the 2nd buyer to also agree to financing terms; which would be the same as me (the 1st buyer). 

Make sure any lease agreement you use complies with Arizona's landlord-tenant laws, including required disclosures (like bed bug information, for example).If you're unsure, consulting with a local real estate attorney to review the agreement can provide peace of mind and ensure you're fully protected.

I told her that I’d hire her at her minimum required salary and give her a small signing bonus.

Multifamily properties do require more management overall and typically appeal to a smaller, investor-focused buyer pool.At my stage, I prefer small MFH over anything else because of the stronger cash flow, scalability, and the more forgiving capex compared to larger MFH, but the best option depends on your goals and strategy. 

Assuming you don't have a mortgage that requires a certain level of insurance, you can get a stop-loss policy covering all the properties. 

The down fall is a Heloc can "Never" be used as an asset or for PITI reserves required when buying a new Primary or investment property.A heloc can also cause major issues with credit and one slight hiccup or missed payment the bank or lender who is holding the Heloc can close or reduce your line of credit.

Fix and Flip -Requires a minimum down payment of 10% with 100% of the rehab financed. 

Another note on construction cost, going vertical is very expensive now and would require have a great connect with a developer and a builder in the area.See what rents are in the area and run the numbers to ensure the rents will cover your costs and give you a solid return—using the 1% rule can help.