buy now button change language

Hi Guys,
First of all I want to say thank you for your good support. It’s really great how fast and helpfull you always are.
I’m having a few issues with the website I’m creating. Problaly it’s a Woocommerce and WPML issue, but maybe you guys can help me.

Now the problems I am having are the following:

1) I’d like to custozise the “buy now” button to “jetzt kaufen” for the german version. where can I do this?

2) I am in the german language…..I place a book into my cart…..all is good…..now I would also like to buy a book in english…..so I change the language into english….but now, because I change to the english language all of a sudden my cart is empty. how can I solve this?

3) When I am here http://meiga.kleiner-mensch.com/shop/?lang=de (german version of the shop)…..on the right side you can see the widget “Authors”. First of all…..why is this widget being displayed? If you check this page in the backend, I have chosen a different widget (translated to german). And secondly, when I select one of the names. The site jumps back to the homepage of the english version. why is this.

I have more issues, but I’ll contact you sepperately.
Thank you so much for your help.
Regards,
mike