Guess I will jump in here. I have a few questions concerning some of the assumptions used in your analysis.
25% for vacancies? Is this Detroit or is the market seriously depressed? What/who are your sources for your vacancy numbers? 25% is extremely strong.
Maintenance is close to 10% which is used by a lot of people. What does the property consist of? Is there grass that needs to be mowed? Trees to be trimmed? My point being is that often with multifamily mowing and other tasks are overseen by management and the cost of maintenance or management(however you want to account for it is higher).
Your current management assumption is roughly 6.8% of gross. Finding good management at these rates in most markets we participate in is unheard of. You should get actual numbers for this. It shouldn't take more than a few phone calls to the larger management firms in the area.
Overall more due diligence is needed, since there are way too many unknowns.