In The Dispossessed by Le Guin, how would you analyze the discussion of the terms “higher” and “more central” in relation to Derrida’s ideas concerning binary oppositions? Does the term “more central” in reality avoid the problem that Shevek identifies with the term “higher”?

Binary oppositions are a part of structuralist thinking that identifies with the human tendency to think in "opposites." Saussure defined binary oppositions as "means by which the units of language have value or meaning" with "each unit... defined against what it is not." Thus, the concepts of positive and negative associations were born: good/evil, male/female, and, in the case of The Dispossessed, superior/inferior.
Derrida believes that such oppositions ultimately overlap and become deconstructed due to their instability. We can clearly see this happening in The Dispossessed when Shevek notes that:

Each [of us] took for granted certain relationships that the other could not see. For instance, this curious matter of superiority and inferiority... they often used the word "higher" as a synonym for "better" in their writing, where an Anarresti would use "more central."

Thus, the binary approach of superior/inferior that was a value system inherent to Urras became one of the major causes of revolution against Urras; as a result, Anarres was formed as a "more central" community that attempted to centralize values between "superior" and "inferior." The trouble with this approach was that the concept of "more central" still operates as a binary in relationship to "less central." The term does nothing to avoid the problem because it still contains an ideological locus.