Correct, you would not want to have a savings account there.
BUT, you WOULD want to take a maximum amount loan right now, they are paying you to take one.
No—they are NOT paying you to take out a loan. They are still charging you interest for that loan.
If all interest rates really were negative (as opposed to just an interbank reference rate like the BOJ’s today) then the best riskless asset would be physical cash.
That’s why they have the idea of the monthly stamp (Gesell), where in an extreme case you would have to buy a stamp each month to affix to the front of your currency. That way it, too, would have a holding cost.