Last three.
18a One coming from average beginning to another world, almost? (7) P - R - E - - PARVENU?
16d Get to 23, perhaps, with point docked (8) (23d NIALL) E - - - L - S - Could be EQUALISE if 18 a is PARVENU.
24d Obscure second book excluded from publisher's promotion (4) - L - R BLUR?
Thanks in advance.