Last one is 20dn and would appreciate some reassurance. Old Father Time volunteers for light work (8) O?E?E?T? Reckon it's operetta. op = work ta = volunteers. Operetta is a light work. But where does the rest come from?
Thanks to you both. I'd noticed pere, ie. father but as there was no reference to French, consider this to be a rather poor clue, as were some others in this crossword.