Are there other ways to move backlog items than using drag and drop?

Yes, you can move backlog items around in the backlog using cut & paste, in the Backlog page. To do this, select one or more backlog items, and use the right-click menu or Ctrl + X / Cmd + X to cut the backlog items. Then move to where you want to place the backlog items, select a backlog item there, and paste the backlog items. This will insert the backlog items at that location, before the backlog item you selected.