(it's not worth depreciating a $35 table, anyway)  Your actual issue is that if you were to be audited, you will not have receipts for things like your Craigslist purchases.Find a CPA who is experienced with real estate for sure.  

They should be able to provide an internal audit.  

And finally, we used an IRS enrolled agent for our taxes, so that if we were audited they could stand in our place with the IRS.

Also if that someone does miss something that's discovered during an audit, they get fined and not me (obviously a pattern will result in a severed relationship, so I keep everything compliant to the best of my ability so that final QC/compliance package is a slow ball I'm pitching their way that they can knock out of the park).

They will do an energy audit and offer you a discount on insulation.

They handle all of the functions that a TPA would do, and are directly regulated and subject to audits. 

OR  Look at the other multifamilies around your area, and take an average of those properties allocation if that is better than yours and document it if you ever get audited. 

As @Lance Lvovsky pointed out, the intention is what IRS will look for if you get audited.

Have you logged hours You need to should detail recording of your hours if audited. 

Additionally, we have used an Enrolled Agent CPA, who can stand in our shoes if we were ever audited by the IRS.My houses are in my profile so you can see how we have progressed.