Having been both a mortgage broker and a mortgage banker for the last 25 + years, I will tell you that the advantage used to be that brokers had access to more loan products and programs and the ability to shop your deal at multiple lenders and in the days of Alt-A and "creative financing" they were your go to source. 

FWIW, if, you’re interested in investment sales (hotels, apartments, shopping centers, etc), you might be able to leverage your accounting education.

Maybe you should start shopping around for other partners so you have multiple people to call upon when a good deal pops up.

How would you redo the floors in the kitchen and the adjacent living area?

If the catastrophic happened, what's stopping the group from liquidating everything and closing up shop?

The vacant unit was previously a BBQ shop/restaurant.

I am assuming some single-man shops may have tax folks that still have the license to do audits from working at a big firm earlier in their career.  

I was shopping a lender to see if they'd find the deal before I submitted an offer and pretty sure it bit me in the ***.  

Should I shop around more?

You should plan to review all the owner's financial statements, review the rent rolls, walk every unit, audit every lease, have contractors inspect the mechanical systems, roofs, create a business plan, review title, review environmental reports, shop all the comps, etcDo you have financing already lined up?