No, zooming your profile picture does not affect its visibility to other users. The magnification is only visible to you.
No, the profile picture zoom function is not available during a live stream. You can only use them if you are on your own profile.
The importance of enlarged profile pictures on Instagram is that they can enhance the first impression you make and emphasize important details of your personality or brand. Use the Instagram profile picture zoom function to ensure that your profile picture is presented optimally and that you can leave a lasting impression.