In Isearch, after hitting C-s a few times, you have to hit DEL a few times to get back to editing the search string.
How can I disable this behavior? I'd like it so that DEL always deletes a character from the search string (the behavior of DEL when you've hit C-s just once [to activate Isearch initially]).
The key C-M-w does what you are asking for. It is bound in isearch-mode-map to isearch-del-char, while DEL is bound to isearch-delete-char.
If you really want DEL to be bound to isearch-del-char then just bind it:
(define-key isearch-mode-map (kbd "DEL") 'isearch-del-char)
Similarly, you could bind C-M-w to isearch-delete-char, if you wanted to:
(define-key isearch-mode-map (kbd "C-M-w") 'isearch-delete-char)
You can find out which keys are bound to which commands in isearch-mode-map or any other keymap using C-h M-k (describe-keymap), if you use library help-fns+.el.
