16/17 (four words in total) is a work by 11 which suggests the remaining unclued lights. Five clues contain a redundant word; these can be rearranged to provide the twenty-two unchecked and cross-checking letters in all unclued entries.
 

Across

 
1    Take lead from better Iraqi writer (6)
5    Opposed awfully stupid ado with journo (8)
10    Headgear as Scottish chill’s endless (4)
12    Religious leader lost heart in harvest (4)
14    Secretary, one keeping distance, is a dish (6)
20    Hindu custom, say, cut short during earthquake (9)
21    Some work as soil almost covers house (7, hyphened)
23    Girl touring meadow runs back wanting foliage (8)
24    Tennis champ’s...