Emacs: 1 Key for M-x
The default key for
execute-extended-command is Alt+x.
On Linux, ▤ Menu key does
execute-extended-command by default.
You should set F8 or ▤ Menu key for it. Single key is easier to type than Alt+x.
For how, see: Emacs: Bind Menu/App Key.
Turn On icomplete-mode
execute-extended-command, you can press the Tab key to show a list of suggestions.
You can turn on
icomplete-mode. It'll show a list of completions automatically.
[see Emacs: Icomplete Mode]