modded-ubuntu/modded-ubuntu ? reverse-engineered prompt

Build me a simple installer script for Termux on Android that sets up a full Ubuntu desktop without root. I want it to download and configure a ready to use Ubuntu environment, then let me start it from Termux with easy commands. The desktop should be lightweight and look nice, using XFCE, and it should work over VNC so I can connect from a phone app like RealVNC or AVNC.

Please make the setup mostly automatic, with prompts for a username and VNC password, and include start and stop commands for the desktop session. It would be great if common things like web browsing and audio work well out of the box, and if the install is modular enough to add or remove desktop extras easily. Also include a clean uninstall or remove script. If you need to check current Termux or Ubuntu setup details, look up the latest docs online first.