"What do you like more – reading or writing?"
Translation:Co lubicie bardziej – czytanie czy pisanie?
No, "więcej" is used for number or amount of something. "Bardziej" describes intensity.
No , bardziej is for verbs, adverbs and adjectives ( more "very", more "very much" ), więcej for nouns (more "many" , more "much")
The English word "more" expresses two concepts: quality and quantity. Bardziej is just for quality, whereas więcej is just for quantity.
If you read carefully, you will see that this question has already been answered in the comment section.