Idea: Why not put search box bellow bookmarks button where you can type text to search from bookmarks the same way you can search with Emacs or bash.

... and why not extend it also to replace normal find (ctrl+f)?

Maybe you could state switching button on some menu to switch keyboard mode.

(sorry submitted the previous by accident)

mode 1: normal mode
mode 2: bookmark search mode
mode 3: web page search mode
mode 4: search engine search mode (opens some box when you press any key)