Hello,
1) Check what fields you have translated http://prntscr.com/gv7ysj SEO fields, not the content http://prntscr.com/gv7zqa
2) Yes. When you do the translation you need also disable the sidebar if you don’t need it on that page.
3) This version of XStore theme does not fully support WPML translation editor for the page elements, that’s why use the default editor or wait for theme update where we add this option.
Regards