1. I cannot find any setting to opt out of email notifications when there are new comments in a thread.
2. The notifications are not very useful, just a link to the thread. They would be more useful if they included the text of the response.
On Feedback #1, are you looking for notification adjustments on phone? Or computer? On the computer, you can deselect what you prefer not to see, including email notifications on thread comments.
"Notify me when people comment on discussions I've participated in."
The bottom option:
@Morganza you have to scroll to the right on your phone. I made a post about improving email notifications if you want to check it out. Maybe Niantic will tag that.