i tend to use 'thread' to mean the first topic post, and all of the replies that follow. i think that's in part because some topics will start with specific questions, then move off to other questions. but, i'm foolish, so it won't surprise me if that's 'wrong'.
good to know i wasn't the only one thinking link-type sub-forums might work, as your example is roughly what i was thinking. the only thing different the OP may want that i can think of is that they don't post seperate from the forum's topics.
please do not PM me to ask for help. thanks.