1 - I can't play any radio stations. I remember being able to listen to the on-demand shows but as of now they don't work either.

2 - Music videos don't play at all.

3 - When i start playing music, i can't access other pages e.g. home, new, all playlists etc. They get stuck loading indefinitely. I can access pages i've opened before starting the playback though, and sometimes some playlists or albums.

Started using Cider in september and pretty much all these were present then and haven't been fixed. Or is it an issue with my system? Am I missing some dependencies or packages?

Using the Appimage version 3.1.8 on Arch.

Do the developers even read these posts?

try using the native version. Its possible to download (pacman). To install the app you need using this command in terminal (within same folder):

sudo pacman -U cider-v3.1.8-linux-x64.pkg.tar.zst

for music videos look at properties / experiments -> enable Library Music Videos