I was told not to be greedy, which is fine, so the overall profit on my end I went down on.

Can i charge 150$ as an application fee but set rents at 10% lower than market to get the best possible tenant and profit off the rest?

Also, make sure you hold on to a property as a rental so you don't end up being designated as an IRS "dealer" (a tax term) that takes about 1/2 of your profits.

Specifically relating to 2-4 unit multi-family buildings, is it conventional practice for the owner to simply pay for water, sewer, and trash or is it conventional practice to bill these expenses back to tenants? 

Check with an independent ERISA tax attorney before you start on this project, and do not simply take the word of the internet or a plan provider that a 75-25 JV deal is OK. 

Then he bought something larger and added some value during one year sold it for a profit of 200 K, plus he wholesaled again and made 50 K. now he invest the 250 k and bought a million dollar property adds value, plus wholesaling deals for 50 k in this year and then he decides to sell again. 

Had he simply paid me the 95K he owed me my company and my insurance would have taken good care of him.

So there would of been potential for $400 profit for some passive income.

The way to make real estate easy is to tell everyone how easy real estate is, and profiting from people's desperation.

I think of turnkey as having all the work done, the tenant vetted & in, property management in place and the property producing a profit in a decent neighborhood.