Thank you very much! 🙂
1. There are a lot of dlna renderer apps available for Android 2.x and the Raspberry Pi. At the moment I don’t think this feature is important for many users, as you can also launch a second app on the speaker device for this… Or did I get you wrong?
2. Supporting the system audio is a very often requested feature. But you need root access to capture the system sound on Android. I have already tested some ways to get this working (maybe as xposed module). I can’t promise anything yet, but as the Google Music support is now completed, I will look into this in the next weeks.
But adding support for Amazon cloud storages (for non-rooted devices) is also a nice idea.