Do not start trying to edit the template files - this will inevitably lead to problems. The Turtle settings already provide a way to control this. If you don't want the file name to be displayed with the slide image (the large display):
To control whether it appears under the thumbnail:
BTW, your other settings all look OK. The only one I'd be a little cautious about is Album > Settings > Advanced > Metadata > Title source > IPTC Object Name.
If you're using an image management program and entering titles for your images, they might be stored in the IPTC, so this might be exactly what you want. But if you're entering your own titles in jAlbum, you don't want it picking up the IPTC stuff, which can sometimes contain garbage left over from somewhere else, like a title that says, "Adobe."