But I assume your screening standards require you to weed out many tenants before you actually rent out the place.

No formal standard exists for classifying a building.

What are some standard protections a buyer should look for once the project is complete?

Is this standard or common practice?

Agents not having the experience in our field, combined with not having the oversight of professionals held to higher ethical standards (CPMs, GRIs, RMPs, MPMs), will most likely not have your best interest in mind but only that ultimate commission.

No matter what, my belief for 80-90% of investors should be:1.

Although this is a common belief, usually fostered from experience, it is actually not that restrictive. 

You want to make sure the people that you rent to will take care of your property and will be able and willing to pay their rent each and every month on time.You can set your own standards with the back ground check company regarding each area such as requiring income of 3x monthly rent, requiring a certain credit score, etc.

You can lend to an LLC and not worry about Dodd Frank as business to business lending is exempt from Dodd Frank compliance however be careful because the borrower already informed you that they are planning to live in the house (walk like a duck is a duck caution).By the way realtor forms have Seller Financing standard addendum to the contract which is pretty clear on the compliance terms. 

Can you reach out to the caretaker's company and ask what the standard practice is for their other clients?