batch audio + picture slideshow video creation for youtube
Is there a tool that will do it, probably... is there a tool that will do it well and make it anything worth watching? No.  

Making a quality slideshow set to music requires manual timing and ordering and a fair bit of effort on the editor's part.  It isn't something you can simply automate away.  If you don't put in the effort to make something good, it will just be adding a bunch more Youtube slideshow trash to the already large pile of Youtube slideshow trash.