@Scott Pollock it's actually within FHA acceptable guidelines to have a 2nd fha loan if your situation has changed unexpectedly as long as the new subject property is 100 miles away from your current fha primary home.

In addition, investigate how much you can really rent the other units for by looking up comparable rents in the area.Bonus Tip:Always save at least 1-3% of the value of your home for unexpected expenses, even if you're house hacking.

We have a young family and don't want to get in over our heads on debt should something go south (and don't want to be over leveraged if we decide to move to a new primary)40% was where we felt good about the cash flow, and can be relatively sure we wont be losing money each month even if something unexpected goes wrong, and we have it sitting in the bank from a stock sell off.

With these extra items however, we feel that 50% fairly captures their unexpected nature while still allowing for our rehab plans to be possible" or similar.

I will guess that by the time you get building permits and complete your improvements your cost will b no less than $250,000 and you lost one year of rental income and you will have to pay for utilities for a whole year and maybe run into many huge unexpected expenses.If you really want honest opinions then post all the realistic numbers for your plan.

So yes, typically you will need all plans signed off on by a P.E.The third common component is a study showing that the additional fill placed in the flood zone by your planned building will not significantly decrease the water holding volume of the floodplain (in addition with other permitted or built fills in the same basin).

The structure you are looking at works fine so long as the asset generates sufficient cash to cover expenses; however, as all RE investors know, the unexpected furnace malfunction or roof failure requires injection of outside capital. 

When were the major systems and structure components updated (HVAC, roof, electric)Once you answer those and are comfortable with the answers from the other guys questions, you should be good. 

The intangibles of how they are in person, is the critical component  and why IMO I'd never just go off what they are like on paper.

Following well drafted contracts and insurance for the unexpected provide the first line of protection.