The best banks that I have found based on your main concerns are smaller, regional, community sized banks.

Meaning, the bank wants to see that a property cash flows for typically one to two years of tax returns before they count it as income. 

Of course most GPs have personally put in money to keep the deals from sinking.

While some strategies may work here, those strategies might not suit you.I don't personally do MTR, STR, co-living, or other nuanced strategies.

Are you referring to personal losses or other people had losses?

You're only talking to banks.

Commercial Revenue Generating properties like office buildings, apartment buildings, retail centers, etc (banks call it "CRE" lending) are typically evaluated from their net operating income, not gross.

Whether the seller was open to a buyer commission or not, I wouldn't put an additional cost into any personal purchase.  

I own a mortgage company now that does both residential and commercial finance, but I spent years as a commercial banker with both big banks (First Union/Wachovia) and 2 community banks.

It should be from someone who uses that person.