One thing that would be really great is if we could quickly link to specific predefined topics or posts. So if e.g. I type GravityBox, Touchscreen Test or Battery while writing a post, I automatically get a popup asking me if I want to link the word to GravityBox, Touchscreen Test or Battery.
That bothers me too. Why have blogs with comments enabled where you need a different login than the forum if you could simply start a topic discussing that blog post in the forum and link it to the blog post.
You mean a Category for Wikis? I suggested that a long time ago but could never get a majority behind that idea.