Since the Japanese doesn't capture the rather nasty euphemism of the original English, and as it stands it's an uncommon A+B compound, it may as well go.

I don't think it's needed.

303 results google web results for "過酷尋問"
Seems to me that this term was coined as a translation specifically for "enhanced interrogation." All the usages that I see are related to the american government.
Not sure it's worth keeping

Google N-gram Corpus Counts
╭─ーーーーーーー─┬─────╮
│ 過酷な尋問　　 │ 241 │
│ 過酷尋問　　　 │  27 │
│ 苛酷尋問　　　 │   0 │
│ かこくじんもん │   0 │
╰─ーーーーーーー─┴─────╯

@@ -11,0 +12 @@
+<misc>&rare;</misc>

perhaps "enhanced interrogation" should be removed altogether

"enhanced interrogation" is an evasive English euphemism. The Japanese means something like "harsh interrogation", so perhaps that should be the main gloss.

@@ -11,0 +12 @@
+<gloss>harsh interrogation</gloss>