I wish there was some measure of how many buyers there are that didn't get to purchase/close so we could get a fuller picture.

. - stuff barely touched in current thread.There is no one-size-fits-all - the risk threshold is a subjective measure particular to each individual.

You are no longer a direct mail virgin.Of course, a campaign typically consists of multiple letter drops, perhaps in sequence with a strategic message and multiple touches, maybe using other media  such as Mail >Call > Knock.Marketing is a year-round effort and should not stop now, think through how you want your targets yo respond to you, how you will capture theit contact info, and what you wish to determine in a phone call.Don't forget yo measure and test the results."

What other safety measures do you recommend?

This will be measured semi-annually to ensure compliance.

Why do realtors not measure anymore?

Quote from @Bob Foglia: Here's an article with specific measurement requirements for egress windows: https://www.coloradowindowsour...Contact the Denver building inspector office and confirm this is their standard. 

I measure my rentals based on my annual ROI.annual net cash flow + market appreciation + tax depreciation + debt reduction (paid by the tenant) divide by my total investment

$99 first month/Free first month etc were becoming more and more common.The same screening measures were in place, but the tenant base was still the same.

Or the other one I my mentor actually made me do in order for him to assist me, he had to measure my commitment.