In accountant talk: Acost segregation study identifies and reclassifies personal property assets to shorten the depreciation time for taxation purposes, which reduces current income tax obligations.

The market was still strong and we were selling but all of a sudden our HELOCs were being reduced or evaporating. 

This leads to lower turnover and reduced costs for the owner (less in makeover costs, less vacancies, etc).  

Why would any person in business reduce their income to make a undesirable tenant "fit".

As you reduce the number of things that a lender "cares" about, the cost rises. 

You could also buy points when you refi, to reduce the monthly payment further.Or pay off a car loan.

If anything comes up during the inspection, you can still back out or reduce your offer to account for the issue.

The nice thing about duplexes is that the lender will take into account the fact that 75% of the rental income from the other side of the property can be used to offset your qualifying ratios, so in this case they can use 75% of the rentals $750.00 income to reduce the amount you must earn to qualify for what appears to be an unaffordable loan.

Or do you take it out for 10-15 years paying off the mtg more quickly but reducing your monthly cash flow.

I like the idea of using other elements around the stone to elevate and reduce the prominence of stone.