Hello,
1) Edit mobile header and remove the promo text element from the top header area https://prnt.sc/1wz6q3m It’s not necessary to keep it there if you use header banner area to show the promo line.
2) All categories element displays menu that you chose in the element settings. So, if you want to change something in the list you need to go to Appearance > Menus and edit the menu that you chose to show for All departments.
Regards