1) Language and currency switchers on our demo are just for demonstration purposes to show the customer that there is area where he will be able to add these things if he use plugins that include such switchers. You can find it in Appearance > Widgets > Left top bar widget area, add the language and currency switchers to that area to display switchers in the top bar.
2), 3) We can offer you only widget areas – Shop sidebar and Single product page sidebar. If you want to place the switchers in other place contact plugins author to find out if they have any additional options for these purposes. As we know WPML has built-in currency switcher and has option to show it on the single product page. We are not sure about another plugin that you mentioned.
Also, keep in mind that styles of the language and currency switcher could be different than on our demo because of the settings of the plugins that you use to get switchers but as a rule plugins have options to edit the styles, plugin support will be able to guide you.