Those surveys ARE meant to be confidential and the crew member, despite having the best intentions, was wrong to confront you about your responses.
I fear that if customers were being approached and challenged about their answers on a regular basis, we'd have trouble finding willing surveyees than we already do.
Regarding the treck to the galley, please, remember the CREW CALL BELL in your handset. In all cabins (though particularly in First and Club) we have absolutely no problem with people using it. It's what it's there for!!!!
I hope your next experience in First will be more enjoyable.