As a Dutch person (in Holland licorice is pretty popular too), I can tell from personal experience that there should be put a big emphasis on "licorice =>COULDI have had periods where I would easily eat a bag oe more of this stuff on a daily basis and for prolonged periods, without even a single hint of the mentioned symptoms, nor anything else that could be related the claimed underlying problem. I also don't recall anyone else with such problems, other than maybe people with a horrible overall lifestyle combined with a taste for licorice.
Very well possible that these are particular conditions (like overall shitty lifestyle and addiction to sugar/carbs) that would make licorice potentially harmful. However, at that point, someone will probably have plenty of other things to worry about.
I'm by no means disputing that this stuff can cause serious problems for individual people. But I also know plenty of cases, myself being one of those, where even copious amounts of licorice caused no (discernible) problems whatsoever.
That itself should questioning the validity of any claimed toxicity, which might only occur under specific circumstances. One might argue that eating sugary candies all day and maybe little proper nutrients aside, could be more of a "cause" than the licorice itself. Even if compounds inside licorice might exacerbate problems even further.