In terms of criticisms of utilitarianism, I have more often seen them made from the right than the left (though more often still from varied not-really-right-or-left-coded angles). I suspect that this may be in large part due to the social circles that I spend time in being somewhat more to the right on average than yours. Nonetheless, it is interesting to see the criticisms you mentioned raised, as they are very much a different set from the criticisms I usually encounter.
Second, as a partial steelman of Rulesianism (or at least something adjacent to it), there are Schelling fence concerns with many wealth tax proposals, where they, by virtue of opening a new avenue of taxation on assets that had previously been considered "already taxed", erode trust in the stability of the overall system by poking holes in the previously-established tax regime, while adjustments such as raising income tax create a lesser degree of such concerns, due to the lack of "double-dipping". This is not to say that the expected benefit of a wealth tax could not still be positive (and given the utilitarian concerns, it very well could be).
Lastly, the section about the practical confluence of interests of different branches of philosophical utilitarianism in a common political utilitarianism is reminiscent of https://slatestarcodex.com/2018/09/25/the-tails-coming-apart-as-metaphor-for-life/ but going in the opposite direction (moving from Extremistan to Mediocristan, if you will), where instead of the focus lying on the divergence of common interests in extreme circumstances, it instead lies on the confluence of interest in ordinary circumstances.
A few thoughts about this:
In terms of criticisms of utilitarianism, I have more often seen them made from the right than the left (though more often still from varied not-really-right-or-left-coded angles). I suspect that this may be in large part due to the social circles that I spend time in being somewhat more to the right on average than yours. Nonetheless, it is interesting to see the criticisms you mentioned raised, as they are very much a different set from the criticisms I usually encounter.
Second, as a partial steelman of Rulesianism (or at least something adjacent to it), there are Schelling fence concerns with many wealth tax proposals, where they, by virtue of opening a new avenue of taxation on assets that had previously been considered "already taxed", erode trust in the stability of the overall system by poking holes in the previously-established tax regime, while adjustments such as raising income tax create a lesser degree of such concerns, due to the lack of "double-dipping". This is not to say that the expected benefit of a wealth tax could not still be positive (and given the utilitarian concerns, it very well could be).
Lastly, the section about the practical confluence of interests of different branches of philosophical utilitarianism in a common political utilitarianism is reminiscent of https://slatestarcodex.com/2018/09/25/the-tails-coming-apart-as-metaphor-for-life/ but going in the opposite direction (moving from Extremistan to Mediocristan, if you will), where instead of the focus lying on the divergence of common interests in extreme circumstances, it instead lies on the confluence of interest in ordinary circumstances.