They may not be able to use financing contingencies and may have to show proof of funds equal to the acquisition price but the money that hits the sellers bank account is the same whether its "cash" or a financed transaction. 

I’ll flip anything where the numbers work.

The jobs are plentiful.

As mentioned, you probably have to skip condos, and you REALLY want to look up the local laws AND the HOA CC&Rs. 

All except one sold for the highest price point at the time of sale.

The loan officer told me to come in the day after settlement to apply.

Stessa for the rentals, Monarch for the other accounts (IRAs, brokerage accounts, cash, etc.)

All of the things you suggest are options to the beneficiaries. 

Congrats on the volume!

If you do want to go this route, make sure that the underwriting of the investment property pays back both its mortgage and the monthly HELOC.