There is no reason you can't discuss any of those topics on the .LRN Q&A forum. Feel free to start any discussion you like.
The major issue with multiple forums in a community this size is fragmentation. We already tried splitting off a CMS forum and it was not very successful. Noone posts there and noone reads it. It is not clear we have enough community members to create many specialized forums.
We discussd this with Philip (one of the creators of the original ACS) and its pretty clear having many specialized forums is not ideal.
So for now, please discuss all user interface and usability issues right here! The community is well aware of the need to improve usability of the applications of OpenACS and .LRN.
