FYI for editing multiline inputs there is a readline key command edit-and-execute-command that opens your $EDITOR with the currently typed command. I mapped it to C-x C-e, not sure what is the default key, if any.

For history I recommend fzf, it's easy to integrate and has one of the most efficient interfaces I've seen. Replaced my ctrl-r with it.

For copying I personally use a tmux binding that dumps the current screen into vim, letting me navigate quickly with easymotion and a mapping that automatically synchronizes the @t register with tmux clipboard.