Should we use the "discussion" tab in the Main Page or the forum regarding a page? For I feel I am posting a lot of threads...
Also
I believe you should have all the composers on one page of the composer list, or at least make it more obvious that there are more on the list. I also believe a single column list with links to each Alphabetical category. Such as This wiki article. Or even just make it more obvious.
1. You can choose to use the forum or to use the discussion tab of a page. Chances are bigger that your thread on the forum will be read. The discussions on the tab should be specifically about the subject of that page. And better not use the discussion tab of general pages like the main page.
2. I do not really understand your question. could you clarify it? Do you mean this page? http://www.imslp.org/wiki/Category:Composers.
Actually, this has been a case that I wanted to fix (currently there are exactly 200 composers, and so it's just enough; I deleted a few empty composer pages).
Anyway, there will likely be a fix for this soon, which would be a horrible and ugly (code-wise) hack (the Composer category probably hardcoded) but I guess it would work... currently thinking of a more elegant way to fix this, but that might not be possible.
Also, for page issues and most things that are temporary, it is technically much better to use the forums. This is because the forums are *much less expensive* in terms of computer resource usage. For example, if you edit a wiki page, the entire page has to be saved (this can sometimes be pretty big!), but in a forum only the new post is added. In this sense it is much more efficient to use forums if you want thread-like discussions that are temporary. Not to mention forums are much faster in the first place.
Wikis are better for information which need to be stored for a long time, like publication information, a detailed analysis of a piece, etc.
Hmm... it might be nice to create a thread with quick question and answers (kinda like a FAQ), but generally it doesn't matter too much how many threads are in the forum (they are designed to contain many threads in the first place).
