Student Centered Speaking Lesson

Every second Friday at my workplace we have something called TOPIC BASED DISCUSSION.
It used to be on Monday mornings, which is a much better time for deep classroom discussions such as garbage/recycling and great leaders (some of my past topics). As Friday afternoon is often Freaky Friday with the kids and Fatigued Friday with the adults I decided to try something different.
This lesson with done with my homeroom, which is eight English Teachers from Jeollanamdo.
I wrote the following instructions on the board:
1. The class will choose a topic for discussion. "What topic would you like to discuss?"
2. Each student will write one question onto the piece of paper (supplied by the instructor) related to the topic.
3. The teacher will collect all the questions and put them into a tin.
4. Then five students will each select a question for class discussion. We will pick the questions one at a time and then talk.
5. Decide if we want to talk in pairs, groups or together as a class.
6. Chat time.

I decided that I would choose one student to suggest a topic and see if we could get class agreement (consensus) on the topic. One could also use invitations to bid and invitations to reply to get a topic as well. The original topic chosen was food but after some further discussion it was changed to homeroom cafe (Is this dialogic discourse?).
The class choose to talk about the topic and the five chosen questions as a class (together).
I used individual nominations to select the questions. Sadly , this seems to be a default pattern for me and I need to open it up to invitations to bid and reply more often. I have started doing this more in class combined with individual nominations during this week (March 31st-April 4th) compared to other weeks this semester. Each student who choose a question read it to the class.
The one good thing that came out of this class was that after the question was asked I stood back a bit and let the students take control of the discussion. As I familiar with my homeroom after almost four weeks, and I see them everyday I felt that giving them control of the discussion was an example of student initiated interaction. Why? They asked each other follow-up questions, and used some of the eliciting functions such as: confirming, agreeing and committing. My role was to decide when to move onto the next question if I felt the discussion was wavering. However, as the discussion was so good and animated we only did three questions in the end.
I should add that the questions for the most part were referential. I had no idea what the students would say. Maybe only my question was open: "Who is the best photographer in the class?" and the question was thrown back into the tin by me and the students. Too simple.