I agree that Trump was a symptom of discontent. Working class Republicans were fed up with the Bush era politics, driven largely because economic inequality has been growing in the U.S. for the last thirty years. The rich are getting richer. The traditional Republican answer is trickle down theory - that even if the rich are growing richer, the rest are getting a boost too. However, that answer has been less and less accepted.
But how different are Trump's economic policies in practice for the average American?
Half of Trump's policy - and his biggest legislative agenda - was the traditional Republican playbook -- increase government spending and cut taxes across the board, running up the deficit. (The median American got around $1000 from the cuts, but the top 1% got $50,000.)
Where he departs from traditional is in his trade wars and restricted immigration. The benefit of those to the average American is unclear. I don't have a strong opinion, and opinion from economists seems highly varied.
Trump's support seems to draw from the same vein of discontent that led to the Tea Party movement. Saying it's about economic inequality is true to some degree, but it's looking at it from the wrong perspective. Because that's a very leftist way of looking at things, and they're not seeing it in terms of class struggles or whether some distant people are getting rich. They're more concerned about their own lives, and how they're doing in comparison to their parents and grandparents. So for them, it's more about the decline of Main Street and rural America, and the loss of jobs and opportunities. Andrew Yang's solutions are silly, but he diagnosed the problem pretty well in his book
The War on Normal People. A lot of middle America has turned into an economic wasteland, with the young leaving if they can.
This decline is the result of a number of factors, including free trade and outsourcing, the shift from an industrial to a service economy, increasing automation, and the acceleration of all of the above with the growth of internet commerce and machine learning. Their boogeyman isn't the rich, it's the elites. Education, especially at elite schools with the concomitant connections and opportunities, is more of a dividing line that raw income. The increasing intrusion of the government on both economic and cultural matters has also led to a resentment of the technocratic elites in the federal government, regardless of their ostensible salaries.
The original Occupy movement was a mix of this, rightist libertarians, and leftist (pseudo?)anarchists. The three groups were reacting to the same core issues, but with very different perspectives and very different solutions. The libertarians focused more on opportunities, and opposed the Fed and state intervention. The leftists were more focused on economic inequality and class politics, and started pushing identity politics hard. That led to the other two groups disassociating themselves from the movement, turning Occupy into a hardcore anti(pro?)-authoritarian leftist movement.
I'm not very clear on Trump's real political views. In a lot of ways, he seems like a typical New York liberal, who doesn't care in the slightest about religious traditionalism or race. His stance on immigration is hard to reconcile with this, but can be explained by political opportunism -- he found an untapped vein of discontent, and exploited it. His appeal to evangelicals is similar: They know he's not one of them, but he'll speak to them and work with them, whereas the rest of the political establishment either bitterly opposes or treats them as an embarrassment.
But that doesn't really explain the birther nonsense, which was long before he became a political demagogue. I think he's really just a businessman, looking for opportunities and worried about competition. He's for free markets in the sense he wants to run a business and do well, but it's the nose in the weeds practical perspective, rather than a sky-high theoretical view from above. That's why he seems oblivious to the damage done by things like monetary inflation, because he has no theoretical grounding; and he's fine with stimulus packages, because he likes handing out things to his friends. He's has no problem with protectionism, as long it favors him or his allies.
I think there's less of a divide over the trade war with China than you think. The political and journalistic classes hate it because it comes from Trump, but even when NPR was interviewing trade officials or import/expert business heads, they couldn't find any who would flat-out say it was bad. They weren't confident that Trump's tactics were going to work, and they knew in the short term it would hurt, but they believed it was far past time someone stood up to China and all their unfair practices. Among economists, some supported the political establishment by saying China is bad and we need to do something, but Trump is still bad because he should have done it a bit differently; and some on the strong free market side will always argue in favor of unilaterally reducing all tariffs to zero; but most seem to think it's at least somewhat justified.