Emacs: 1 Key for M-x
The default key for
execute-extended-command is Alt+x.
This command is most frequently used. You should set a single key for it. Single key is easier to type than Alt+x.
You can set F8 or ▤ Menu key to do
On Linux, ▤ Menu key does
execute-extended-command by default.
For how, see: Emacs: Bind Menu/App Key.