up a half step; enharmonic reinterpretation—an augmented-sixth chord in m. 61 is reinterpreted as Sc: V7 resolving to VI (note that Mozart notates the reinterpreted version of the harmony, not the augmented-six in B-flat minor)
m. 69; one measure
m. 49; 59, eliding with the beginning of the core
an antecedent (mm. 49–52) is followed by a continuation leading to an evaded cadence (m. 56); the repeat of the continuation ("one more time") concludes with a PAC (m. 59)
m. 72; by means of a home-key half cadence
no; the recapitulation starts immediately after the HC in m. 72