You don't need to use complex graphics or video motion tools to create backgrounds for YouTube end screens. Instead, you can simply use Keynote and build a single-slide presentation with animation. It is fairly easy to get elements lined up with placeholders and then to play around with various animations to make your end screen look great. Then you can export as a movie and add it to the end of your YouTube videos as you finish editing them.
I always wondered how this kind of thing was done. Thanks, Gary!