Your name shows up as the login name you chose when you joined Network54. The only way to change that is to get a new login name, make it Premier, then have them swap all of your forums over to that login name. You will lose all of the realm files you have under the first login name (well, not really, you just won't have them within the new login).
To add your logo, you can either link to it directly from your admin page (if it's already online somewhere, on a site you own or have legal rights to hotlink from) or you must first upload it to your realm, then link to it from your admin page. Look here for more info on how to do that http://www.ripper1.com/nw54/images.php
