I pretty much agree with what you say, except the assumption that the history of the Roman Empire has much of anything to say about the future of America.
The Empire was a slave-based, non-technological, human muscle based economy. It’s difficult to think of anything at all its economy had in common with ours, except of course for pervasive corruption and cronyism. The Empire certainly did not have anything even vaguely resembling progressive taxation or extensive welfare.
In fact under the Empire the wealthiest people were generally exempt from most taxes.
Let us not get too caught up in minutiae.
Yes, it was a different time, but the Obama administration is continuing a long line of Leftist Central Planning with the tacit assumption that they are “progressive” and therefore forward-looking. In fact, they are making mistakes that were made centuries ago.
They are exemplifying a mindset that distrusts popular will and consider it to be an impediment that must be thwarted if it cannot be manipulated. A government that is not legitimated by a popular mandate is always going to be a threat to the economy. If it is only possible to gain economic success if one also has political influence, the socio-economic order will be medieval; the vast majority will be poor, ignorant and disenfranchised lorded over by an arrogant and detached elite.
When their policies fail, they never take responsibility, blaming freedom instead. They are the ones who stand for the elite and it is the poor and middle class who will suffer the most. Only the super-rich can withstand the flat wages and soaring cost of living that result from collectivist statism.
What the current situation in America and throughout the Western world shares in common with Classical Rome is that this is unsustainable and our entire civilization can collapse as a result.
Indeed, on our present path, collapse is all but inevitable.