Open discussion on the best format to interact between users.

We want to add discussions, conversations between the followers of a channel. We have the following options :
1- Comments
People comment on a specific posts mostly like facebook, twitter, instagram.. Comments are hidden within the posts, and specific to a post in a feed. The issue with comments is that older posts comments are difficult to access.
2- Chat
People talk in a general chat for the channel with a simple conversation interface. The issue with chat is that it can get messy very fast.
3- Discussions
People open discussions on a specific topic, they can invite people from the channel and it appears on the feed. Like Reddit, Quora. The issue with discussion is a heavier process with opening a discussion, setting a topic and eventually invite people to talk about the topic.
We would like to have your thoughts about this important feature.
Thanks
The discussions we were thinking about are more like reddit discussions, it is a post within Knil created by a follower of a channel who wants to discuss something he saw in the feed.
In the discussion the user can invite specific people or create an open discussion. The idea is to have live interactions between the users within the feed.
Ok we are solving this in next release with "- see all your likes (not only 50)"
The limitation for me is not in the number of channels, or the number of interests per channel: I have troubles creating even a single channel with a few interests, because I have to pick them from my liked Facebook pages that are several hundreds, and the "Edit channel" page only shows the first 50 (I counted them), so the list stops at the first of my liked pages starting with the letter 'B'. This is in my opinion a major usability issue, that should be taken into account before new implementation... and I think that I am even less than average, in term of numbers of liked pages and friends on Facebook, as I can see from close friends.
We are uploading a new release on Sunday with
- Modified limitation to 30 channels of 100 interests each
- relationships channels to follow friends and family
- invite followers to your channel
- see all your likes (not only 50)
What is missing in this list for you to use Knil ?
Frankly, at the moment I can hardly imagine how the discussion feature could work. I have looked into Knil as a powerful social network aggregator and filter, but the limitations I have wrote about currently prevent me from using it as such - so, I am not using it at all yet! :/ That said, when I'll be able to use Knil as an aggregator, how would I like to discuss inside Knil? Since the contents is coming from outside Knil, how can a discussion *inside* Knil integrate in discussions generated from the outside contents? Shall I discuss inside Knil instead of, or in addition to, discussing in the original networks where the posts come from? Again, I have to start using it before I can make up my mind about the subject...