Depends on the size of the portfolio you intend to build, whether you have lots of capital now or will be buying slowly and steadily (like me), the mix of property types (multi-family vs single family), and your financial goals and exit strategy (pure cash flow versus balanced cash flow and appreciation).Generally, diversification is good.

So I just went under contract on my first property that I bought purely from an investing standpoint.

I have no ego attached to this, it's purely a numbers game.

Interestingly, because of how high the cash flow is on the property, the amount that she DID pay covers the mortgage, escrow, insurance, property taxes and PM fee of 9 percent on the entire property....and since it's a duplex then what the other tenant pays is pure cash flow.

I would investigate.The rockwool insulation your friend suggests, the stuff made by Owens Corning, is called Pure Safety.

You can approach this in a purely business fashion and bring it to market rents now so you aren’t losing any money.

Is it purely a psychological show of intent? 

The cost of living is already pretty low, so I would go purely off of the average rent per sq ft in your neighborhood. 

Loopnet is like that but on steriods.The proforma number are pure poop.

Just depends on various factors...if you are looking at it purely from an investment standpoint, I think it's just so-so.