I want to place “already open comment box” below last reply so user can reply quickly and have more attractive on this. How to do it?
It’s possible, but fairly complex to do. The best route is probably to have it custom developed. You can talk to a developer in the #marketplace category about possibly doing that. One word of advanced warning – doing something like this may require a lot of long-term maintenance, as a major interactive change can break easily if any methods you’re using from Discourse core changes.
Alot of social network site have this function by default, very surprise that Discourse do not.
While there are some similarities Discourse isn’t exactly a social network and is meant to be focused on longer discussions.
The composer gives you the benefit of being able to scroll through the current topic or even visit other topics while you’re writing. We have no plans to change this, so if it’s a necessity you’ll need some custom work.