> I was brought up to work diligently, not take on debt, and save - a simple approach to building wealth - but I'm concerned that will put me at a disadvantage under an economic system with negative rates.

Interesting take. Why would you be at a disadvantage and to whom would this be in relation to? I think it's fair to say that in the very long term inflation, etc will erode the value of your cash, but I imagine that there is still value in saving. I'm not sure these rates will last forever anyway.