But do the house has to be ALMOST identical?

This contract is almost identical to the one I use except mine does state the closing company.

You could have two identical properties, with one stuck in a horrible electric contract and the other on a great rate.  

With them not being identical though I'd be more inclined to treat it somewhat like a basement unit or such rather than typical 50/50 duplex.

(Not a big deal in that price range, but the point being, it's personal property.)Landlords that expect their property to be handed back in identical condition or better aren't facing the reality of the business, part of your rents charged is for repairs and upkeep from normal use that should be expected.

Side payments (undeclared to the bank) on a short sale constitute fraud, but there may be a way to give the owner a reasonable amount of walking money, I don't know.

The fees are the minute hand, the rate is the hour hand. 2 hours and 60 minutes, and 3 hours, on the back end, are identical.

That’s not to say you can’t house hack and rent out a spare room but what you are describing is mortgage fraud.  

Now, if you are doing new construction, then yes, an average price per SF for the size of your home in that area will get you darn close, but on a rehab, only twice a day which is the only two times a broken clock is correct.Think about it, two identical houses with same square footage on same street, yet one needs new roof, new plumbing, and foundation repairs while the other does not.

Marcia my landlord history and past track record is almost identical to yours.