Colludium
Not exactly a 'how do i'.. I was thinking of something in the lines of a 'Here's a neat trick i found' or 'I encountered this bug and solved it by doing so and so..' , Obviously the forum section wouldn't be named as such but that's what i intended to mean. My first post is actually very vague now that i look back at it.
Like a wiki as you mentioned. Just a place where users can post tips/tricks/bugs and their quick fixes. Unfixable bugs would obviously go to the Bugs section. Not a place to ask but rather a place to explore themselves.
In my case i found a problem where , when pinning two sprites with revolution joints (Physics behavior) , the sprites might be in the desired position relative to each other, as set in C2 and when previewed on a desktop, but when previewed on phone via cocoonjs app, the sprites get offset my some amount no matter what, even if you put conditions to set their position. Then i found that the sprite's position of it's collision polygons was the culprit and by trial and error and modifying the collision points i was able to get it to be in the desired position as it was when previewed on the browser.
Now i found that bug and solved it myself but i didn't think of posting it anywhere, then i thought what if others found and solved other quirky bugs or have some shortcuts which they use for certain types of games, we are all a bit selfish/lazy.
But as you said it will be a load on the mods and i'm not even gonna pretend to know how to run a site, but i thought it might be a useful section.