Re: Fanzines.
I do not work for Mongoose (except on a very occasional freelance basis) and this is not an official answer, just my own (very) humble opinion. This might sound a bit nasty in places, but it's not intended to (apart from where it is)
First off, submit everything to S&P - it's free to everyone so there's no reason to put anything in a fanzine unless they reject it. You also get paid.
Don't do anything else unless S&P rejects the article.
If that happens, I'd stick to what the SRD and the RQ logo licence allow you to do - invent towns, races, etc that could fit into Glorantha without directly referencing anything Glorantha-specific (yes this means no mentions of cults, nations, gods, or anything else of that nature). These have been provided in order to allow people to legally use someone elses IP.
If you really, positively, have to infringe on IP and post free Glorantha material, then to the best of my knowledge Mongoose have never told anyone to take down material based on any of their licenced game settings (B5, Dredd, SST) when posted on the web. If they do sue you, do not blame me. Do not blame Mongoose either, as large sections of IP law are dependant on protecting your IP whether you want to or not, or you lose all rights to said IP. Just to be a little safer, I'd keep it in emails and members-only yahoo groups where it's not a "public" infringement and is more a sharing of information between like-minded players of the game. That way you're making copies for personal use and not publishing the material, and this might (only might) have a diminishing effect on the legal penalties the court applies if the worst happens.
Note: This is not me providing ways to hide yourself from the law. This is me trying to inform people how said law works. Judges are human beings (whatever else you may have been told) and might (only might) take a far more serious view of something with worldwide distribution to the general public than a group of people "innocently" sharing IP-derived material without permission.
The only thing you should 100% avoid doing is putting stuff in a printed fanzine that charges for distribution (even just to cover printing costs), or a website that charges you to access it (even just to cover bandwidth). Either give it away at the authors expense as their contribution to the hobby or don't do it at all, because the second money changes hands it's a whole new ball game legally.
Finally, if you want a proper answer rather than my uneducated essay on the subject, email Matthew Sprange at Mongoose (msprange@mongoosepublishing.com) and actually ask for permission to do whatever it is you want to do - the worst that can happen is that he says "no".