I would request that you build a roadmap on your webpage, stating the various plans you have and appropriate current prioritization. If possible, allow registered users to add comments/votes.
My comments on your answers above:
1) Am I correct in assuming that this data as such is not valuable without voice identification? Are there ways to anonymize this - just asking.
The website talks vaguely about turning over to authorities, but more details in the privacy policy would assuage some of our fears.
2) You might want the user to download that data, and then get it off your system. Saves your space, liability etc without possibly impacting the app.
If the user wants highly accurate data, he leaves it there. Otherwise he deletes it. The onus should be on the user.
3) I don't think this is mentioned on your site?
4) Awesome!