Firstly thanks for the answers, a few more to get to finish
12a chief among everything else to start with.. (5,2,3)first,??,?l?
27a such excesses will catch you flat-footed (4-4)b?o?-??t?
29a sounds like an instrument youd play back,but its one thats used by others (4)??o?
23d it would be a stand-offish reception you might get from a polar bear (6)??????