As someone largely involved in this topic, I feel keeping everything in one topic (unless it gets too big for the message boards*) makes things easier, since you can just use the search feature to find stuff. The only separate topic I would say we need is for a compendium of relevant Greg Quotes, like what we have for Tuyet.
*and at the rate we’re going, of about 2500 posts per contest, we should hit 30000 posts (the number that shut down the Bionicle 2016 topic) right around the last contest of this list.
In terms of making specific discussion easier to find, perhaps the posts where you ask questions that generate discussion could be linked to in the OP? For example:
Discussion about Tuyet’s sword, Nui Stone, and re-entering old contest entries: post 6918
Discussion about separating entries by Prime Tuyet, DM Tuyet, or both: post 7945
Both posts have an amount of relevant discussion afterward, plus several direct replies.
As for having a separate topic for list 2, I do think it would be a good idea. For one, this topic may hit 30000 posts by then. Two, if someone’s looking for a post/discussion about one of the list 2 characters, they don’t have to search through all the posts about the list one characters (since the search function starts with the earliest posts).