Hey Thomas,
first of all, thank you for the purchase!
In case you wish to have the language switcher on the background slider page, this page at WPML details the functions and calls to implement it. If you have no experience with php, you can tell me the website’s URL, the exact place where you want the language switch to be, and send the admin login and password to support@satoristudio.net – and I’ll insert it for you.
It is also worth noting that the background slider is not the only type of page that is possible to have as a front page – in fact, you can set any page of any template as the front page, by going to the “Settings -> Reading” admin menu.
Sincerely,
Andrew | Satori Studio