Selection

Select a text line or text frame

Press ctrl and click the text line or text frame

Extend or shorten the selection

Press shift and click an object

Force selection border to appear (when dragging from outside all objects is not possible)

Press ctrl+shift and drag diagonally

Select the first object in the draw order

esc o shift+f

Select the next object in the draw order

esc o n

Extend the selection to the next object in the draw order

esc o e

Deselect a text frame or text line and put the insertion point inside it instead

Double-click in the text frame or text line