Best practices in sharing qualitative data such as interview transcripts alongside a paper publication?
If your research data comes from people, your sharing of the data needs to be approved through an ethical review process, or an exemption from that process must be obtained through the exemption process.
CSV format seems to be the most reliable data format; it does not matter if your data is quantitative of qualitative.  Your choice of repository should be guided by the customs of your field and your views of the repository's reliability, not the type of data.