Sorry, can't dig through all of that post. I do not think it is an ad verecundiam fallacy. There is legitimate criticism that "trump has little to no political experience. Especially in foreign policy". Contrast to Hiliary Clinton where she apparently wrote more than 30,000 e-mails on department of state business. While writing 50,000 pages she probably put some thought into the subject. Also consider Sanders. He avoids foreign policy. He refuses to talk about Hilary's e-mails. Instead Sanders insists that Americans want to hear about economic issues.
Trump has a lifetime of experience poorly investing his father's fortune. He has experience with multiple bankruptcies. Most candidates just write a check to a financial adviser. Trump gets involved with his casinos and golf courses. It think it is clear that a president Trump would result in more documented 7.25$ wage workers paying taxes. These 7.25$ jobs will become available because millionaires will hire them with the money they save on corporate tax cuts. Sanders' supporters agree with Trump supporters about what discussion matters in a presidential campaign: 15$ minimum wage not paying and taxes on billionaires.
If you are primarily focused on economic policy to the exclusion of foreign policy then business experience becomes a somewhat relevant background.