I need some serious help with this damned Raspberry Pi4

[bluesman]

Not all RPi operating system images come with networking or SSH active.  If this is the reason you can't access it, you can activate SSH like this:

1. Power off your Raspberry Pi and remove the SD card.
2. Insert the SD card into your computer’s card reader.
3. Navigate to the SD card boot directory using your OS file manager (or from the command line if on a Linux box or a Mac.
4. Create a new empty file named ssh, without any extension, inside the boot directory.
5. Remove the SD card from your computer and put it in your Raspberry Pi.
6. Power on your Pi board. On boot Pi will check whether this file exists and if it does, SSH will be enabled and the file is removed.

Unless there's something seriously wrong with your Pi 4 (which is bvery unusual), you should be able to bring it back to its original spec and functionality by putting the latest Raspberry Pi OS on a good SD card, booting up, installing and configuring it, and updating your firmware.  If that works fine, you should be able to use DietPi, Ropiee, and any other audio JEOS.  In case you don't know how to update its kernel and firmware, it's easy:

• sudo apt update
• sudo apt full-upgrade
• reboot

Until the latest image came out, the 64 bit RPi OS was incomplete and had enough bugs to cause the problems you're describing.   Audio was problematic, and USB was not fully operational.  But if you go to the 64 bit downloads page ( https://downloads.raspberrypi.org/raspios_arm64/images/ ), you'll now find an image that should work fine for network access and most audio although VLC is still not there.  I didn't know that NAA was available for a Pi.  When I last looked at the Siganalyst site, there was nothing at all about a Pi in the NAA section.

 

The 64 bit RPi OS does put some library files in different locations than the 32 bit versions do.  As a result, Roon Bridge will not even install on it without moving several files.  I see a link in the Roon community forum to  https://www.signalyst.eu/bins/hqplayerd/images/hqplayer-embedded-4.18.0-raspberrypi4.7z , but I can't access it to find out whether it's a 32 bit or 64 bit image.  Unless something's changed recently, you have to run the 32 bit to use Roon Bridge on a Pi.