My at-the-top-of-my-head answers:
1/ Who are your favourite writers?
Tolstoy, Jane Austen, Melville, Nabokov, Flaubert, Emily Bronte, Gogol...
2/ Who were your favourite writers when you were a teenager? Which of them do you still like?
Late teens: Haruki Murakami, Elfriede Jelinek, Milan Kundera, Franz Kafka, Isabel Allende, Patrick Suskind, Toni Morrison, F. Scott Fitzgerald, J. D. Salinger, Gabriel Garcia Marquez, Phạm Thị Hoài, George Orwell, etc.
Early teens: Charlotte Bronte, Marc Levy, Guillaume Musso, Aziz Nesin, Nguyễn Nhật Ánh, Nguyễn Ngọc Thuần, Paulo Coelho, etc.
I still like: Kafka, probably Fitzgerald, Salinger, Marquez, Orwell and Toni Morrison, whom I haven't read for some time. I have complex feelings about Charlotte Bronte.
3/ Which writers have most influenced you?
Tolstoy, Nabokov, Jane Austen.
4/ Which writers do you wish had not influenced you?
Can't think of anyone.
5/ Which writers are you embarrassed you used to like?
Dan Brown and Marc Levy.
6/ Which writers did you not expect to like, but did?
7/ Which writers do you think you will still read, and like, for the rest of your life?
Tolstoy definitely. Perhaps Jane Austen and Nabokov. Not sure about Melville but Moby Dick will always have a special place in my heart.
8/ Who are your favourite prose stylists? Or your favourite writers on the sentence level?
Melville, Nabokov, Virginia Woolf, Robert Louis Stevenson.
9/ Who are your favourite writers of characters?
Tolstoy and Nabokov. George Eliot, but her moralising narrator should be out of the way. Also Jane Austen but she's different.
10/ Which writers, alive or dead, would you invite to dinner?
Chekhov and Turgenev. Perhaps Fitzgerald.
11/ Which writers, alive or dead, would you like to know personally? And think you could be friends with?
Nabokov, Emily Bronte, Chekhov, Salinger... Dostoyevsky and Gogol because they're nutters. Jane Austen I wouldn't have dared to meet. I don't think I could have been friends with any of them.
12/ Do you personally know any published author?
Vietnamese: Phạm Thị Hoài and Vũ Thư Hiên. Foreign: Matthew Selwyn. I don't count Viet Thanh Nguyen (author of The Sympathizer) though he's on my facebook friend list.
13/ Which writers do you like/ admire but generally avoid, for some reason?
Nabokov and Melville, because they're geniuses and I'm not always up for a challenge. Flaubert, because of his misanthropy and pessimism. George Eliot, because of her moralism. Henry James, because of his lengthy sentences, his rambles. Dostoyevsky, because obviously.
14/ Which writers do you like as critics/ essayists but not as novelists?
15/ Which writers have changed you as a reader?
Tolstoy and Nabokov.
16/ Who do you think are overrated?
Murakami, Kundera, John Green.
17/ Who do you think are underrated and should be more widely read?
Salinger's short stories. I don't know. But Tolstoy and Melville would be more widely read.
18/ Who do you think are the best living writers?
Can't say. But definitely not Murakami or Chimamanda Ngozi Adichie.
19/ Which writers do you go to for comfort?
Jane Austen and Lewis Carroll.
20/ Which writers do you go to for mere amusement?
I only read serious novels because life's short and I'm a slow reader.
21/ Who are the greatest writers that you don't personally like/ that you just don't warm to?
Dostoyevsky, George Eliot, Henry James.
22/ Which writers do you hate/ strongly dislike?
Stephenie Meyer and E. L. James. Gayl Jones, E. L. Doctorow, perhaps Joyce Carol Oates.
23/ Which writers are you prejudiced against?
Hemingway, Knausgård, Naipaul, Ayn Rand, Michel Houellebecq, Bukowski. I also have some prejudices against the author I'm reading- Chimamanda Ngozi Adichie.
24/ Which writers do you feel you should have read by now?
Now that would be a long list: Nguyễn Du, James Joyce, Proust, Dante, Cervantes, Oscar Wilde... It would be a very very long list.
25/ Which writers from your country would you recommend to a foreigner?
Vietnam: Nam Cao, Phạm Thị Hoài, Nguyễn Huy Thiệp. But note that I'm an ignoramus as regards to Vietnamese literature.
26/ Which writers do you recommend to everyone? Every serious reader?
Tolstoy, Melville, Flaubert, Nabokov, Dostoyevsky, George Eliot, Henry James...
27/ Which writers do you wish you could write like?
I will not answer this question.
28/ What is your favourite language to read in?
29/ Which foreign-language writers make you wish to learn their language in order to read them in the original?
Russian, because of Tolstoy, Gogol, Leskov, Chekhov... French because of Flaubert. German because of Kafka and Patrick Suskind.
30/ Who is the best writer you've just discovered recently?
If recently means 1 year, Melville. More recent, nobody great.
Compare to my answers in 2021.