> - If we don't want to flash that message, the message can be displayed and
> be allowed to stay there till user starts/resumes typing in the minibuffer.
This will be fixed by bug#12988. I'll send the latest patch there.
I don't know how you're planning on solving doing this, but I was going to suggest that isearch could just take over the mode-line while in effect, that would it give it a lot of space to verbosely display the searching options (and maybe even list the key binds for each) and each option could be a button that toggles itself.