[Snow]

In the main window, I can't exit the text boxes at the left side without losing my current selection, because the only way these text boxes loose their focus is to click somewhere in the view windows.

In the TCE, the text boxes loose their focus as soon as the mouse cursor is moved away from the boxes.

The behavior of user interface elements should be homogeneous throughout the whole application.

Nonetheless both methods are bad.
Why not use the 'Return' or 'Enter' key to complete the entry in a text box and free the focus from that box? That's why some clever people invented these keys.