Deal Calculation Factors - Brooklyn, NY

Some questions for people who invest specifically in Brooklyn, NY. 

I'm looking into small multi-family properties with 3-4 units. 

Ideally in one of the following neighborhoods:

 Bushwick, Ridgewood, Williamsburg, Bedstuy, Clinton Hill, Crown Heights, Prospect Heights, and the surrounding areas. 

1. What numbers should I realistically aim for in cash flow and cap rate?
2. What and how much should I include in my expenses? (besides taxes)

Cold water? Electricity? (The tenants pay for their own gas, electricity, hot water)

Snow shoveling I'm assuming that the super of the building will do which is within the PM charges?

4. How much do property management companies take in Brooklyn?

Thanks!