The statement from the devs applies pretty broadly to “hands-free” use.
The much more common solution for folks who want to be audio-only or screen-free when studying (which is all your use case of running seems to require) is to use a small wireless remote to interact with the app. That would require no code changes, and is something you should look into.
I doubt that toggling Auto Advance qualifies as something a Bluetooth or Android device would view as a play/pause action for media-control purposes.
If there’s any chance of it working, I think you’d probably have to set up your Bluetooth device to function as a controller in AnkiDroid, with toggle Auto Advance tied to a button. If your device will do it – that’s already supported. If it won’t – see the suggestion above about using an actual controller.
You already have adequate functionality to control the order that New cards are introduced – Deck Options - Anki Manual .
You shouldn’t study Review cards in a set order. Can I study my cards in a particular order? - Anki FAQs
And if you have multiple audio forms on the same card, they will already all be played.
Although I think it’s unlikely this request will be taken up, I’m going to point out the issues here.
- Easy should definitely not be your most common rating – Studying - Anki Manual .
- Your numbering is the reverse of the standard keyboard shortcuts for the grades, and of how those grades are coded in the system – 1-Again, 2-Hard, 3-Good, 4-Easy. That seems almost deliberately confusing.