You know, as far as events go, players are able to do a lot more than GM's can since they are not bound to the same restrictions. While a player cannot make special items or play as creatures, these things are not needed to make a good, enjoyable event or story. When I played in '09 I remember Tadano Hitoshi - aka Jarexia ran a lot of nice events. They are documented under "In game roleplay events." Other players like Duraza and Jacula did the same and quite well. Jacula's events were very open and often involved many players. People would just join it at random.
When GM's do run events, they need to pre-plan them and have them approved before they can execute them. This takes away from the natural, spontaneous feel occurs in good player led events and stories. Also, GM's are not allowed to casually role play while on as a GM, so when they do run events, their characters tend to spring up out of nowhere. As a player, you have the advantage of being able to slowly role play a character into existence and get them connected with everyone before starting your event. This makes the event or story much more personal and believable.
As a player you can still add in your own props. Tadano was always using quest items as props and integrating bits of information from quests in his stories. We sometimes used books as part of these events. When an item was not available to us, we would just take a book and change its title to match the item. Everyone knew to treat it as if it was that item.
As for playing guards, players should just gather together in character and form a lynch mob if needed. Grab them torches and pitch forks and take the matter into your own hands. It would really suck if the GM guards extinguished each and every conflict - preventing any climax from possibly from occurring. If you have a need for extra guards, then perhaps ask some characters to help out in that respect. Hell, the bad guys work together, why shouldn't the good guys follow suit and do the same? There may even be an IC market for personal and business security guards.
*cough cough* The Outlaws do offer protection *cough* *cough*
Whisper Bless!