I have three that I would appreciate help/ explanation:
2d. Gather nothing in volume post again (9).
I have R_A_P_I_T and feel Reappoint would fit.
26a. Fuss starts to irritate the personnel in prison (7).
I have N_T___K and Nitpick would fit
19d. German opera that's nothing to a frenchman, centres on Zanzibar(6).
I have _I_N_I.