@thorsten: There is no fixed picture dimension for Featured Image Slider as you can make the image slider whole width or just a small one like in basic version.
If you use regular image slider then width is 644px but if you use large full content slider then width is 920px.
You can set the number of slides in the slider through “Slider Options”. There you will see “Number of Slides” input box just type in the number you want.
For opening in new window. It is not currently supported. We have noted down and wil add in future version updates. For now, you need to hire a customizer ( http://catchthemes.com/hire-customizer/ ) or post it in jobs ( http://jobs.wordpress.net/ )