Your comments

For simple upper / lower casing, other editors like TextPad support a much more simple syntax in "replacement expressions":
  • \u  Force the next substituted character to be in upper case.
  • \l  Force the next substituted character to be in lower case.
  • \U  Force all subsequent substituted characters to be in upper case.
  • \L  Force all subsequent substituted characters to be in lower case.
  • \E or \e  Turns off previous \U or \L.
Agree.
There should be a setting that prevents the Find menu (Search / Replace) from auto-hiding all the time.