Emacs keymap questions

1. I typically hit Escape twice to switch out of Quick Documentation
Lookup, Quick Definition Lookup and autocompletion popup windows. Is
there an easier-to-reach key that would do this? What command can I
assign a keybinding to to customize this?

2. Ctrl+N/P allows me to cycle through autocompletion choices. Why
doesn't it allow me to cycle through Go To->Implementation, File, Class,
Symbol choices?

Omair