First and foremost, the reputation and history of the sponsor should be a main concern.

So they have to decide .. history will prove though that most will just continue to bleed a slow death and just like when a stock tanks you sell and reposition..

I think it depends on your lender for Zone X, which they can require if there is history of flooding, and other higher risk areas are Mandatory.

But I am a history buff.

Of course, if the individual borrower has a checkered history (bankrupticies, foreclusures, felonies, etc.) there might be an issue.

Because eager China and hungry India are not just catching up, they're kicking our complacent American/European butts ;-)

Denver is kind of an anomaly and it very well could be the next major American city years from now. 

(i) Limited or No History of Rental Income Where the Borrower does not have a history of Rental Income from the subject since the previous tax filing: Two- to Four-Units The Mortgagee must verify and document the proposed Rental Income by obtaining an appraisal showing fair market rent (use Fannie Mae Form 1025/Freddie Mac Form 72, Small Residential Income Property Appraisal Report) and, if available, the prospective leases.

If the house has been vacant there is likely a history of problems related to it.

This strategy will depend on other things such as a healthy W2 income, rental history, otherwise low DTI ratio, etc.