Quick clues; 14a Essential commodity (6) -t-p--
12d Rashness (8) ---e---y (temerity)?
21a Wise men (4) -a-- ( last letter i if temerity correct )
Cryptic clues; 15d What strange skill will get across (7) i-h-a--
23a Endlessly give one's attention to the boss (4) ---d