Piczel notifies you about things in two ways: notifications on the site, and emails. Both are controlled from your notification settings, in separate sections.
Your user icon at the top right of the page is a dropdown with notifications for what happens on the site: new followers, comments and replies, favorites, multistream invites and the occasional site announcement. There is a clear-all button, and your browser can show these as push notifications if you enable it.
The switches under Notifications in your settings decide which of these you get: going live, gallery posts, new followers, comments and replies, favorites, multistream invites, and announcements from Piczel. They also control what the digest email includes.
Receive emails from Piczel is the master switch: turn it off and Piczel stops emailing you with the exception of things like password resets or premium purchases.
Each email type also has its own switch:
These decide what following someone subscribes you to: their going live, their announcements, their posts, and whether posts they favorite show for you. Changing them never touches follows you already have - each follow keeps its own per-person switches in your follows list, with bulk toggles to change them all at once. See Follows and followers.