OK, so this is very minor, but:

I can never remember that it's called tool-bar-mode, and not toolbar-mode.  This
is not often an annoyance, but it hits me every time I'm on "emacs -Q" or
similar.  (I type "M-x toolb TAB TAB TAB", have a revelation and then, "DEL -bar
TAB".)

Both "toolbar" and "tool bar" are valid spellings AFAICT.

I suggest to introduce a new (defalias 'toolbar-mode 'tool-bar-mode) to
accommodate users who are used to either spelling.

Thanks,
Stefan Kangas