Answer:
To delete a load case, use the navigator or select "File" → "Model Data" from the drop-down menu.
In the navigator, go to "Load Cases and Combinations" → "Load Cases", right-click the load case you want to delete, and select "Delete". The automatic relocation of the next load case instead of the deleted one is not possible.
The easiest way to sort load cases is to use the table. To do this, simply select and copy the respective rows and paste them into the desired row.
As an alternative, you can also use the "Renumber → Move" function to re-sort the load cases.