1) As I suggested, can you make it show the character code when more than one character is selected, as the current specification just shows nothing which is not useful.
2) But why does it leave the highlight from the previous search, as well as highlight the new search ?
3) I can understand if incremental highlighting is disabled, but when enabled it would be preferable IMO to immediately redo the search with the new options (ie. Match Case, Regex). At the moment you force the user to perform multiple steps to redo the search with the new option – ie. a user would change an option, delete/add a character in the search pattern, and then re-add/delete the character to perform the search again. Why not just automatically redo the search ?
NOTE: This only applies if one of the options is changed and Incremental search is enabled.