For your survey, I would suggest reducing the number of categories as someone who drafts surveys in my day job. There are too many categories to sort easily. I might suggest:
Source
Amplification
Speakers
Speaker cables
Interconnect cables
Acoustic room treatment
Those choices alone will generate a wide range of responses. And I agree with @millercarbon that a survey is probably not the right way to answer your friend's question. Your survey results will just likely show that there is a divide between the speaker-first people and the source-first people, while the "truth" probably lies somewhere in between the philosophies of the two groups. As I mentioned above, listening is the only way for your friend to figure out what is the "truth" for him in terms of what part of the system to emphasize.
Source
Amplification
Speakers
Speaker cables
Interconnect cables
Acoustic room treatment
Those choices alone will generate a wide range of responses. And I agree with @millercarbon that a survey is probably not the right way to answer your friend's question. Your survey results will just likely show that there is a divide between the speaker-first people and the source-first people, while the "truth" probably lies somewhere in between the philosophies of the two groups. As I mentioned above, listening is the only way for your friend to figure out what is the "truth" for him in terms of what part of the system to emphasize.