BBC News - Has quantitative easing helped the US economy?

BBC News - Has quantitative easing helped the US economy?

"QE may have been driving down the wholesale cost for banks to make loans, but Wall Street was pocketing most of the extra cash," he argued in the Wall Street Journal last November….From late 2008 until 2010, the Fed bought nearly $2.1 trillion of treasury bonds and mortgage-backed securities.

Now, there are two questions:
When will the Fed finally raise its short-term interest rate, which has been stuck at near-zero since late 2008?
How will the Fed "unwind", or get rid of, the billions of dollars of treasury bonds and mortgage-backed securities that it has purchased?"