How can I get an email notification whenever new answers or comments appear to certain questions that I'm interested in?
Yes, You can get notification for selected tags: read this post on Meta SE.
One option is adding tags to your RSS feed:
Hover over a tag in the Emacs SE tags page then click on the rss icon.
A second option is:
navigate to tags filter page and fill the simple form with the filter details and your email address.