I'm under contract on a commercial deal.

In todays markets the ability to refinance is tough given banks have tightened down on lending, and mortgage (personal or Commercial) rates being what they are.

If there are common areas in the commercial property, then sure you would need to do the accounting regarding who pays what and what's collected among the various tenants. 

I obtained a commercial loan that was a 1 yr interest only and required 25% down which I borrowed from my step father to be repaid after closing plus a $5000 payment.

You listed two but in broader terms financing (assumable, owner financed, sub to, fha, new 95% OO LTV that in most ways is superior to FHA, dscr, F/f conventional, NACA, VA, etc), value adds (development including ADU, upzoning, traditional rehab, sophisticated value adds that leverage localized rules, coop/tic, etc),  property types (residential, commercial residential, land, storage, MHP, industrial, office, camping, hotel/motel, etc), passive/active investment methods (GP, LP, REIT, nnn, self managed, pm, flipping, mineral right, lumber rights, etc), residential rent models (LTR, STR, MTR, rent by room, student housing, arbitrage, etc).  

I lost a listing where an agent told the client that they knew me, which they didn't and said I mostly only do commercial real estate - 98% of my business is residential 4.

Then there is a difference between residential and commercial.

Hey all,I’m currently looking at a mixed-use commercial property that includes some SRO (Single Room Occupancy) units, and I’m running into challenges with financing.

In my case, I have residential rentals in one LLC, commercial properties in another, self storage in a third, and my real estate company operates in a fourth.

I was paid a rather large sum to “teach” Peerstreet finance people commercial loan evaluation and investment.