According to David, who answered my question via mail, it's possible to code my own draggable elements instead of dragging a widget/text with a shortcode.
1. I install a plugin e.g Woocommerce (or other thirdparty plugin)
2. I make a draggable element of the shopping cart, generated by the shortcode: [woocommerce_cart],
3. I do some magic code
4. My users can easily drag a woocommerce shopping cart to their themes.
I was wondering how? And i was wondering if i can place this draggable element in a "new" accordion tab section e.g. "draggable e-commerce elements".