I have an idea for HS01... I need opinions.

Unless it was completely separated from the rest of the site, no.

Is there even much demand for such content on HS01? Personally, I think you'd be fine keeping it limited to official content, especially with the amount of Hero Factory media increasing (particularly with the introduction of the Secret Mission novels).

No. I know from experience. The word fanon attracts noobs. If you do make the namespace, beware.

Just leave it as it is. I mean, the whole point for BS01 being up is simply to be reference, right? As far as I'm concerned, HS01 is fine staying as simply a reference site.

And really, the only "activity" that ever happened on BS01 was mostly just related to downtime fixups, or user stuff on Talkpages or other stuff. xP

The problem is, nobody updates HS01 too much, and back in the day BS01 had several editors a day.

Generally in my experience, the term "fanon" is more reserved for cataloging fan content popular among the fanbase, not for just letting individuals make stuff up as an excuse to drive up site traffic. The only bit of actual "fanon" I know in Hero Factory is the name Daniel Rocka, and I don't want that name anywhere near HS01 except maybe as a trivia note on the Rocka page to state that it is an unofficial name that somehow snuck onto some copies of the Savage Planet DVD.

If nobody updates HS01 that just suggests that a) users are busy (this applies in my case; I edit very rarely because of schoolwork and other obligations) or users aren't passionate enough about the source material to consider it worth their time. My guess is there's a combination of the two. It doesn't help that there hasn't been much non-paid HF story media in months, besides brief and often confusing LEGO Club website updates.

The main way the site will see more editing, IMO, is if more people buy the Hero Factory Secret Mission chapter books and start adding content from those. After all, those are very good (every bit as entertaining as the BIONICLE books IMO), and the depth of them is too much for any one editor (read: me) to handle. But all in all, I see no logic in expecting that we'll see more productive edits as a result of creating a completely non-productive namespace for editing. If anything I'd expect that to serve as a distraction from following the actual Hero Factory story.