I could see getting rid of the sub-forum.

However, I would keep the spoiler tags. They should still be used for the first week that an episode comes out or when discussing leaks for upcoming episodes, assuming this is all going under a general thread for ongoing series. If it's a thread for a specific episode or to discuss future events, than a spoiler warning should be put in the Thread Title and a reminder in the first post that potential spoilers will be discussed.