Besides that, I find it a bit strange that Search settings are influenced by an Auto-completion checkbox in the “Entry editor” preferences.
When auto-completion is checked, the Search becomes case sensitive by default. As long as what you enter in the search bar does not trigger the autocomplete drop-down, the user cannot change case sensitivity.
With respect to the three buttons on the bottom of the auto complete part: the “.*” and the “abc” ones remain the same when clicked, so there is no feedback indicating the current state. (only the button on the right is changed when clicked, alternating between “float” and “filter”).