Don't forget about capital expenditures (Cap Ex-replacing worn out items-dishwasher, water heater, etc).  

Hard to figure what cap expenditures or improvements would cost more, but of course I wouldn’t know until full due diligence.  

If your monthly PASSIVE cash flow is greater than your monthly expenditures, you are generally wealthy.

Prabodh Kumar kandala - the structural will last well over a hundred years but maintenance and HOa's can get expensive due to maintenance and capital expendituresThe condo should have a budget and a capital expenditure report and a condo reserve analysis which shows expected life and cost for large expenditures

A list of responsibilities for the PM should be in your agreement - - the more the merrier, as that's a primary reason to use a PM - - off load work & responsibilities.There should also be a list of line items which are considered 'petty cash' expenditures with a fixed dollar limit per incident and you don't question or challenge.Beyond petty cash, expenses need a Purchase Order, itemized, date of completion noted and specifically which person/contractor(s) will supply the service. 

If you've not left out any deferred capital expenditures, that's a fantastic setup. $25k for $1350/gross rent?

So my interpretation of what he says would be to find highly sought out areas (depending on your investment strategy), and analyze deals in such a way that if you were to find a less than desirable property (C or D) and are able to rehab it to that of a (B) then factor in desirability v/s market v/s expenditures to result in the highest ROI.

We drew up a partnership agreement outlining share percentages, roles/responsibilities, clauses in case of death or incapacity, Right of First Refusal in the event that we want to dissolve the partnership, capital call provisions (needing additional funds), written approval from members for expenditures over "X" dollars, etc.

The pipes will be a constant maintenance expenditure, and the main is a ticking time bomb that will cost tens of thousands of dollars to replace and require emptying the entire building, and taking out the floor of several bottom floor apartments.The math nerd in me wants to quantify the risk - what's the likelihood of the main going while I own it (I only plan to own 2-3 yrs), how many replaced pipes per year average at what cost per break, etc.

There is a ton of great information on this site about estimating expenses, but here are a few items you'll probably want to account for in addition to the mortgage/financing costs:Property taxesInsuranceVacancy factorRepairsCapital expenditures (major repairs)Property management