In some situations, a lender will allow for someone who didn't originate the loan to continue making payments, until the lender changes their mind.

The in home test kit reliability is questionable unless they can provide peer reviewed test validation data.

As a general rule of thumb, I usually strive to keep about 2-3 months of mortgage payment reserves. 

I’m in the PAYE repayment program where your payment is based on your income.

This is the best way to do it in my opinion as your payment is lower and there is no PMI. 

Was never 100 percent sure if you could or not, but can you theoretically house hack a commercial property (such as an apartment building) in order to get the low down payment? 

The one's that I have spoken with normally offer free consultations but won't honor it in this case and are demanding payment up front before they can even confirm whether or not they can do it.

that would lower your down payment requirements - you could keep your primary as a rental, and move into a househack. 

However, it would provide us with the necessary funds for the repairs and potentially a down payment on another property.

@Josh ShamoiliaWith a large loan you will have a large payment that will effect your cash flow.