Hey Blaubär, thanks you've solved all my issues! Got the previous/next buttons, I was able to exclude all the whatsapp speechthings, and the list is smaller (I could swear I have tried compact more than once...). As for the music not being found I would like to clarify that Im fairly sure it's not a Poweramp issue. If you google for the issue more people have this with several players (which some can resolve by deleting a .nomedia file, but that didnt help me, alas).
Thanks again for making the player great again!