I'm trying to design it to be self-sufficient and self-repairing on a long-term perspective, but as you can likely imagine, it's impossible to know for how long exactly it'll work, and we don't have the time to test it out.

[ He'd like to offer a more definitive answer on that front— alas. ]

So far as I know, the creatures are the only beings living in Ceta. And unless they understand basic technology, no, they wouldn't be able to fix anything. But if all goes according to plan, it won't need to be maintained or operated.