The ten unclued lights consist of a theme word and three groups of three answers of a kind, each group relating differently to the theme word. Unchecked and cross-checking letters in these answers could make TAX AUDITOR APPROVE.
 

Across

 
1    Cuttingly, John dissects fancy style (8)
10    Escape with loot is dicey in Catholic’s area (12, two words)
13    Two pianos are for old man (7)
17    One eats a bit with a king and queen (8)
21    Chemist’s glum with rain streaming (8)
23    Little 4 blocks hearing (7)
25    Where to learn one plus one (3)
29    Excitable, touring Crete and French island (8)
34    Rotating arms and...