As if owning a SFR magically makes you immune to sudden large costs. 

Not really any magic sign here, the lower the rent the more responses it really is that simple. 

.#3 – Time (Post Close)When I first started purchasing single family rental homes, I thought getting a property manager would magically bring the amount of time I spent managing the asset down to zero, wishful thinking right?

If they magically do issue one, you must accept it, but they won't.

There is also some magic formula that is used, I believe the rehab loan would be around 70% of the after repair value (ARV). 

So I need to use the magic of OPM (other peoples money).

I've yet to see a spreadsheet proving a HELoC as some special, magical lending vehicle; if there is one here on BP, please post a link.   

Is there some kind of magic to the number 5 I’m unaware of?

If you have to much consumer debt, I.E. credit cards, installment loans, car payments things of that nature, then just get rid of $133.00 a month in debts to get down to the magical 45% that, that lender wants the debt ratio at?

There is no psychological trick to make someone magically want to sell.