It would be good to be able to move/copy/delete/etc. multiple files in the tree view at once using combinations such as:

Mouse

• shift+left click: Select all items from the currently focused item to the clicked item
• ctrl+left click: Add the clicked item to the selection

Keyboard

• shift+↑: Add the item above the focused item to the selection (or reduce the selection)
• shift+↓: Add the item below the focused item to the selection (or reduce the selection)
• ctrl+↑: Move the focus up without selecting the item
• ctrl+↓: Move the focus down without selecting the item
• ctrl+space: Add/remove the focused item from the selection