and sometimes there are hanging containers or containers that consume too much RAM.

Hmmm yes, but can't you see it in CLearML dashboard ?

unless I explicitly add container name in container arguments, it will have a random name,
it would be great if we could set default container name for each experiment (e.g., experiment id)

Sounds like a great feature! with little implementation work 🙂 Can you add a GitHub issue on clearml-agent ?