There's nothing fringe about observing that there hasn't been hyperinflation or analyzing the reasons for a lack of hyperinflation. Many erroneously predicted dramatic price inflation due to the similarly dramatic inflation of the money supply. The "Dollar Milkshake Theory" offers plausible answers to the questions you posed above. We shouldn't have to evaluate it as some kind of gospel truth. Instead, individuals who have an interest in the topic can examine it, take what they may, perhaps build their own ideas upon it or reject it based upon their own rational thoughts.
If you have no interest in engaging in a good faith discussion or if you have no interest in examining the answers to those questions, perhaps you shouldn't pose them in an open discussion. The premise is disingenuous and obnoxious. If there's no room for rational discussion or examination, what is left is by default irrational. If there's no curiosity or interest, there's no reason to pose the questions.
There's nothing sales-y about his talks. From what I've heard he's generally expressed a lack of interest in promoting his services in those forums. Instead he engages with others who disagree. He debates with academic economists. He debates with doomsayers who are explicitly selling fear. Would you have us believe that academics are also pitching investments? That professors who are publishing free to access papers are going to hoodwink you out of your savings? Your language here would suggest as much.
Even if he were selling something, are you so fragile that you cannot endure a salesman's pitch to learn the details of the product? Who else would be considered a domain expert, if not academic economists and the traders who put macroeconomic theories into practice?
For those who are genuinely curious as to the mechanisms driving markets, it wouldn't be unreasonable to examine to the thoughts of domain experts. I suppose then, if we cannot examine the ideas of the domain experts, we should build our own layman theories and ideas out of whole cloth? If that's your position, invoking the fringe accusation becomes doubly ironic.
Throwing around pejoratives doesn't move the discussion forward. It is both obnoxious and toxic.
The characterization driving your prejudicial dismissal is inaccurate. Worse yet, "The Dollar Milkshake Theory" supports your general sentiment against doom. Perhaps you have your own internal rationalizations for your inaccurate prejudices, but outwardly there's nothing to distinguish your posts from outright trolling. If you possessed even modicum of curiosity or good faith...
All this from a site that puts on airs about the quality of discussion.