As a SFR investor for over 15 years I have been wrestling with this question in the past, because it feels like you should upgrade to "bigger".I know for sure that I would not enjoy the ownership experience that comes with a small 4F, because in Milwaukee that typically also means lower income tenants. 

How much net profit in general should I look for on a long term buy and hold rental property like this?

Cash flow How did you find this deal and how did you negotiate it?

After a couple of weeks, I gave up and hired a prominent local Realtor.If this is your situation, I'd look at one of two options:  1) Figuring out how to make it work as an owner 2) Sell and take the loss.

Not sure how long it's been vacant, but definitely have an Inspection done for any foundation issues, walk the property with a licensed GC to determine the exact SOW.

Sheena Jones: https://growthadvisors-tax.com/Let her know that I referred you.

You always want to think about if this location goes dark how fast and cheap can I lease it.  

What did I miss, and how do I avoid it next time?

I could pull money out from it, but as most will know.

When I first started investing in real estate, I discovered how important it was to identify and capitalize on the right opportunities.