So if there are hyperinflation for inflationary currencies and deflationary spirals for deflationary currencies... is there another type of currencies that avoids these two problems...?
I'm sure you've read the arguments in this forum that bitcoin deflation is not a bad thing.
Rather than repeat those, I'll just point out that an easy solution to the problem is to allow currency competition. You can limit the damage caused by hyperinflation if you allow people to abandon the failed currency for a healthier alternative. That's what you saw in story #2, where they replaced hogge money with tobacco. Argentina's coin shortage could have been dealt with by private organizations issuing their own tokens, possibly backing them up with pesos.