The Core CPI is used to calculate "Core Inflation," which is the main thing that the Federal Reserve tries to monitor. See http://en.wikipedia.org/wiki/Core_inflation. So although there are alternative CPIs which do include food and energy prices, they are not as important to the people making monetary policy in the United States.
I'm not really sure what you're trying to show with that graph of deflation probabilities. If I'm reading it right, the probability of deflation through 2017 is currently 0%. Since the year is currently 2013, the "probability of deflation between 2008 and 2012" is also 0%, since I just lived through those years, and... it didn't happen.
The reason why people were buying treasury bonds in 2008-2012 is because the rest of the economy was imploding and they wanted a safe port in the storm. I lived through those years and so did you. You ought to know this already.
I don't really know what else to say. If you think it's a good idea to buy a bunch of treasury bonds with super-low interest rates in 2013, knock yourself out! I think anyone with an ounce of sense can see that our government is going to inflate away its debts over the next few years. In the meantime, you'll be helping to keep USGov in the black, so... thanks, I guess.