A.E. Russell
I would guess Philip Larkin as the speaker.
DAMNIT.
I’m halfway through Name of the Rose.
I saw this thread, and thought, “Hey, I could chime in. Yay, etc.”
I see #8, something about a medieval monk being poisoned by a book.
I say to myself, “Self, if that’s Name of the Rose, I’ll whine like a crack-addled rhesus monkey.”
Proceeding to whine.
Well all the others I know have already been answered, so…
**
Tony Last, from A Handful of Dust. Take my advice and don’t read it for yourselves.
23 is Graham Greene’s The Power and the Glory.
Six more right answers above. Well, six and a half really:
Eutychus55:
Stephen Daedelus/ Portrait…correct.
The Man Who:
Sherlock Holmes…correct.
pesch:
George {A.E.) Russell…correct.
The Moonstone…correct.
Philip Larkin…correct.
peepthis:
Tony Last…correct*.
Opus1:
The Power and the Glory…correct.
Only five more to go. You can do it:
Unusual Deaths
06. In which novel does a man meet his death by dropping from a balloon’s mooring rope?
Madness
20. Which character has a schizophrenic breakdown in a 1920’s Riviera bathroom, and in which novel?
Drink
24. Mexico again, but this time mescal is the main character’s preferred poison. In which 20th century novel?
Drugs
29. Whose mother’s ashes were mixed with cannabis, and in which book?
Animals
32. ‘We had the old crow over at Hull recently, looking like a Christmas present from Easter Island’. To which of his poetic contemporaries was Philip Larkin referring?
#24 : Under the Volcano by Malcolm Lowry?
Dick Diver in Tender Is The Night by F. Scott Fitzgerald?
Something by Aldous Huxley?
06 The Baron in the Trees
by Italo Calvino, if you need an author.
At least two will qualify with this one a possibly a third.
In Mysterious Island a man falls to his death from a balloon’s mooring rope and the same happens in Five Weeks in a Balloon.
A man also falls to his death from a mooring rope in Master of the World and the vehicle is sort of a ballon.
I imagine someone has said it, but Night of the Igauana.
Eutychus55:
Under the Volcano…correct.
Francesca:
It’s the right book (So I am reliably informed).
sublight and TV time:
I hate questions like this. I read Enduring Love by Ian McEwan a few months ago. The opening chapter features a death which occurs exactly in the manner described. To learn of 4 more possibilities is Bad News. We’ll have to see what happens when the official answers are published.
I am asking a Moderator to withdraw the question. 
Down to the last three.
Madness
20. Which character has a schizophrenic breakdown in a 1920’s Riviera bathroom, and in which novel?
Drugs
29. Whose mother’s ashes were mixed with cannabis, and in which book?
Animals
32. ‘We had the old crow over at Hull recently, looking like a Christmas present from Easter Island’. To which of his poetic contemporaries was Philip Larkin referring?
At a pure guess - since I couldn’t bring myself to read it -is 29) referring to Frank McCourt and “Angela’s Ashes”?
Stein?
Lindberg?
Pound?
wariat and TV time:
Both incorrect. A couple of clues:
29. Maybe I was lucky with this one because I read this book recently as well. It’s by Graham Greene.
32. The poet was British.
Number 29. What is “Travels With My Aunt,” Alex?
OK, wrapping this up now:
20. Francesca had the correct book but the character was Nicole Diver (Tender Is The Night).
pesch is correct with the book and the character is Henry Pulling (Travels With My Aunt).
Philip Larkin said this of Ted Hughes.
Same time next year.