We are a company that performs in-depth surveys.
1. When we collect data on ethnicity (without collecting any other personal data), is this considered as personal data according to GDPR?
2. When we record session cookies, is this considered as personal data according to GDPR?
3. For some clients we do in-depth interviews, and we record either videos or images of the interviewees; we send those videos or images in aggregate form to the client (we send no other personal data), and we do not keep track of which part of the video or which image displays which interviewee. If an interviewee wishes her personal data to be deleted, how is this to be executed on our client side if neither we nor they know which part of the video / which photo belongs to this interviewee?