this is not really possible yet but a good idea. We will work on that in the future.
It is not possible because the URL does not have the number of the active slide attached.
If you really need that feature you can of course program it with jQuery.
It is not really easy but also not impossible.
You can pass through variables with URLS. And then you could call that variable and start the slideshow on that point.
To answer your second question:
It seems like Bureau Kirchner just added a text paragraph with links into the gridder.
The problem they face on small broswers is this: