Is it possible to automatically advance / loop through the playlist?

Yes, but this is a Pro feature. Free users can try this feature for 15 minutes from within the app.

If you go to the “Settings” and “Preferences” menu, you can check “Advance Automatically” under the “General Settings” tab. SlideDog will then advance to the next slide or file automatically (will jump to the next file if at the last slide of a slide deck). Videos will be played until the end before jumping to the next item in the playlist.

To enable looping of the playlist, tick the box next to “Loop Continuously”. SlideDog will now jump back to the first file after completing the last file in the playlist. All files will be re-set and play from the first slide/page/frame.