I’ll also amortize large items like roof over 20 yrs, and then add $100/mo/unit for general repairs.

I use this type of system in a ten unit that I own because the cost to submeter each one was cost prohibitive I usually don’t include other items like wifi/internet unless it’s a furnished/short term rental. 

After adding those four items back in, it brings the complex to making around $6,500.

In general, I would say Kitchen, Bathrooms and any deferred maintenance should be your focused items. 

For example if you were to exit a new build in 5 years there may be no cap ex cost (i can think of few cap ex items that does not last 5 years - maybe carpet in class c and lower), just maintenance costs which would be fairly small.Best wishes

Install cameras and exterior lighting on timers, place no trespassing signs, and place items that indicate occupancy - like a BIG dog bowl near the front door, shoes, etc. 

Would you have any recommendations, in your experience, for what to look out for in the documents that would be red flags or items that would negotiable?

Good summary of what your market is looking for but as we all know, each market tends to have its "wish / want" items which differ from market to market.Flow is definitely a selling point but make adjustments come with a cost. 

The inspections have become so nitpicky over purely cosmetic items there has to be an extra $1-2k per year to keep up with the punch list every 1-2 years.

Never use an Expense Ratio %-  do a line item forecast.