How can I combine whiteboard animation, stop motion and live video without massive import/export and adjustments?
Well in that case you would export the video from VideoScribe and then edit it together with your other video material in an video editing program (also referred to as NLE).
Quite straight forward process, how you do this step by step depends on the video editing software you want to use.

There is the free Lightworks and commercial solutions like Adobe Premiere, Sony Vegas or Apple Final Cut and Apple iMovie.
I'd suggest you look into a solution that looks like it appeals to you and then watch a tutorial on the basics of that program.