The insertion of environment labels is controlled by the LaTeX-label-alist
variable. If you don't want environment labels, theoretically you would need to make that variable nil:
(setq LaTeX-label-alist nil)
Unfortunately, this setting will be overridden for the environments provided by the amsmath
package and the longtable
environment.
A much more coarse solution would be to redefine the LaTeX-label
function to do nothing. Add the following to your .emacs
(eval-after-load "latex"
'(progn
(defun LaTeX-label (env))))
So you'll never be prompted for labels after inserting an environment with C-c C-e or a section with C-c C-s. You'll be able to manually add labels with C-c C-m label
RET as usual.