I would like to thank Wendy and Hannah for raising some important issues.
I am fairly certain that the only choice with the current set up is either to receive notification of all posts to the News and Comment group or by checking the site to select those topics/threads that you wish to subscribe to. I will check with the developers tomorrow on the possibility of a more bespoke set up.
I think the comments also raise some quite difficult issues about striking a balance between allowing people to have their say but at the same time recognising that most discussions/arguments peter out. This is a debate that the TalkPhysics community needs to have and I will reflect on the best way to set this up.