I'd like for all apps to have a command lookup similar to Sublime Text: Type some text to match a command.

The list must be exhaustive -- if it's not there, the command cannot exist. (Unfortunately, Sublime commands are explicitly registered and the list isn't complete; it even lacks core Sublime commands.)

The list should also show keyboard shortcuts and allow a way to modify them in-place. (Sublime doesn't do that either. A real missed opportunity.)