No one can predict prices softening.

I don't think that it is ever going to "pop" as some people say, but it is a good buy and hold area because of the stability of the main employers, which you will be able to predict.  

He predicts that sometime soon it will sink, or correct, the same way that stock market did in October-December of last year.

However, if we could really predict the future with Excel, we'd all be ridiculously wealthy.

I see a strategy of hoarding cash to increase speed of purchases now and refinancing (like a big blanket loan) in a few years to provide a more predictibly paydown period (after growth phase is complete).Is the extra cash worth the rate risk?

Any number of things could happen completely beyond my control to predict and I could be out thousands of dollars in just a few short minutes.I got out of that train wreck.

You can predict the future but the problem lies in the timing of it all.

I clearly state to the tenant that just as much as they cannot predict the future, nor can I, hence as a business I have decided to have leases run for a year. 

There are certainly cash flow plays in DC...but the main play within the city limits is appreciation...and it is not that hard to predict within the district.

Your question regarding incorporating the appropriate rent rate suggests that there is some way to predict where the rents will go.