You're right that QE erodes the savings and income of not-rich people - the middle class and the poor.
You're wrong in your theory that accumulated wealth does nothing. In a QE world, the very rich don't sit on cash - that would mean losing money through currency decreases.
There is no such thing as 'wasted capital' - rich people store their wealth in a variety of vehicles - whether in banks (where it is re-lent out for many uses), public stock ( where it is used for company investment and operations), and private investment, such as investing in pre-IPOD start ups and private equity.
Even Apples massive cash hoard is put to good use, somewhere.
What there is a shortage of, is productive investments where lots of capital can be deployed to get a healthy return. This is a function of multiple problems, of which uncertainty is one.
It's a very cartoonish model to imagine a daddy warbucks with a big pile of cash saying 'I just don't have time to spend this'. In actual fact, there would be a team of investment managers saying 'we can't find any good places to invest, so we're letting the bank invest it for us, for the time being'.
The answer to Japan's problems is cutting government spending and debt. This has always been the answer, this will always be the answer, whether you're an individual with 20k in debt or a country with 200b in debt. The key is to realise that there is no magic Keynes multiplier.