The name's Bond...James Bond.
All good points. There's little doubt that the embargo has not succeeded in its goal of toppling Castro. But, I think you overstate the hostility factor and the international condemnation factor. Most of Western Europe uses the embargo as an opportunity to get into a market free of US competition. They're thus indifferent to the concept from a political POV.
However, there's no denying that the influx of American goods and services helped bring down the USSR. Once people got a taste of the Big Mac, the whole rotten edifice caved in soon after. So, it certainly begs the question of why that approach wasn't tried in Cuba, apart from the obvious answer of "because no one wants to look like they've caved in to Castro".