The Grumpy Editor's video journey part 3: DVD authoring

The Grumpy Editor's video journey part 3: DVD authoring

embed background animations

You just need movie for that, not static picture.

animate menu transitions

Surprisingly does not exist in DVD format. What the "professional" DVDs are doing instead in series of menus:
1. Original menu
2. Transitional menu with no buttons and autojump to 3rd menu at the end
3. Next menu
As you can guess complex menu systems can produce literally hundred of such menus - and that's exactly why such DVDs are pretty expensive to author

easter eggs, changing DVD player settings like subtitles, language, and audio settings

Most of these things are only available if you play directly with DVD VM.

P.S. I've done some work with DVDs and the only thing I can say about this format: it's a mess. Why the hell they need to have 10 copies of everything in different places ? To confuse players if something is not 100% consistent ?

From what you describe, I bet that was the motivation.