How do you get (in one step) from mandatory interest on deferred dividends, to no accumulating dividends and no interest on those non-cumulative dividends that will never be paid anyway?

The dividends are always cumulative, but there is no interest accruing on them under a mandatory deferral of INTEREST situation. Of course, in a bankruptcy the cumulative preferred dividends will never be paid, but we all knew that. There's no bankruptcy in the cards for ING.