According to my research they are the same product but one (DSP11RA) is for german speaking customers. And the other is a more general. Look it up on Google. DSP11RA brings you a german website and the other can be found in english. Searching for DSP11RA in the english site will bring you nothing but in the de_ch one it will.
Chromecast is not on board. Alexa is. I connect the TV via ARC (HDMI) and the network player via HDMI. The mobile phone with Spotify usually via Bluetooth. But it also works via Alexa and Wlan, which doesn't always work for me. Detailed settings and calibration can be done via the app.