can we use the x2go without the nxproxy, the protocol to compress data? Compression is very important feature of NX and X2Go because raw X11 for comfort operation requires rather high bandwidth with low latency. With NX one can work via rather slow connections (just like with RDP). Second important feature (for me it's even more important than compression) is ability to disconnect/reconnect without terminating X11 applications. Proxy is required to achieve these things.
i didn;t understand exactly what is the role of this x server on the application, i didn't find any doc on this. Describing it in simple terms, X server converts X11 commands to real graphics on your screen + sends keyboard/mouse events to X11 clients (actual applications) + implements clipboard.