As a historical narrative it's pretty shameless, e.g. inventing out of whole cloth a second visit to Frege. I also felt that it did not convey well the personalities (let alone the ideas) of the early analytical trinity.
Indeed. The disagreement over abortion is, roughly, whether killing a human fetus should ever be legal. The disagreement is hard to resolve because it’s not clear which principles to apply, so that arguments pro or con can take on a semantic flavor, but there’s nothing semantic about the underlying issue. (It might be that the author harbors some feeling that all ethical questions are merely semantic; this is putting a lot of weight on a distinction which became discredited in 1951).
The Church-Turing proposition carries an implicit challenge: find an algorithm to evaluate a function which is not Turing computable. Because it can be challenged in this way, it’s not just a definition (mere stipulation how to use the word “computable”).