you’re quite right about the update service: its purpose is to check for updates, and it’s not essential for the functioning of the EyeX stack.
The choice of port 9000 wasn’t a good one — thanks for pointing it out to us! — and we plan to change to another port in a later release.
In the mean time you can safely disable the service. Just remember to check the Dev Zone for updates every now and then if you do so.