Just the last few giving me grief :
1A : Thus take advantage of capturing pawn, resulting in mate (6) : S???S?
4A : Lists characters in period pieces (6) ?P?L?S : is it SPELLS?
11A : Something funny about king in court paper (4) : ?R??
21A : Piano accompanying song or two (4) : P?I?
22A : Highly competent guide retraces her path, but not entirely (6) :
?E?R?A : is it PEORIA If so why?
2D : It's inside cover, though not hidden (5) : ??E??
Many thanks in anticipation