Photoshop layers eat up all the DVD laser's time- no room for sound or motion. In other words- they are very creatively limiting and for this reason I do not recommend their use. Studying the manual on how simple highlight layers work and looking at some of your favorite DVDs and you'll realize you can do a lot the other way.
There's a difference between a layered photoshop menu and an overlay. You can use an advanced overlay on a motion menu, but you cannot use any motion at all in a layered menu. The manual is pretty clear about what you can & cannot do with each, & how to use them.