I think Q&A and chat make a nice complement, provided users (both askers and answerers) are disciplined. I don't see what you think is missing and would be solved by a “super-chat”. Here's a good scenario:
- Asker asks a troubleshooting question.
- Someone comments that this is likely to take a lot of back and force and invites the asker to chat (with a link to a specific chat room, either existing or specifically created depending on the usage in your sub-community).
- Some discussion happens on the chat.
The asker updates the question with extra information that he now knows is relevant, and with a link to the chat transcript.
Here's more information, following <link to chat transcript>. Uninstalling and reinstalling the program didn't help. Moving
/path/to/file out of the way did solve the problem, but I lost my configuration. …
People post answers based on that extra information, perhaps summarizing the troubleshooting methodology as well.
Step 4 is very important. A troubleshooting question has two purposes: solving the problem, and teach the asker how to solve this type of problem. In order for the question and answers page to be useful to future visitors, the methodology must be apparent there.
Of course, participating in a troubleshooting session may be more energy than you're willing to spend. Reasonable troubleshooting questions should not be closed as long as the asker sticks around to provide more information upon request. But if noone is willing to spend the energy, askers must be prepared to accept a partial solution, turning “solve my problem” into “what's the first step to resolve this problem”.