Hi guys, thought I'd drop in and raise hell with all this organisation going on and throw a few spanners into the works.
These are just my thoughts, based on human nature and inexperience.
How long will the Gymkhana run for? For example, if it starts at 10am what time does it end??? I know it will depend on how rapidly people get around the course, but if the course is too long (in km's) or too difficult it may take long (in hours) for people to complete it. If Marshalls are req'd, to run it, you need to be sure you can get some.
Could be hard getting Marshalls if it's pissing down rain and is cold.
The less you have to depend on others, the greater chance you have of the event succeeding.
Is the entire course going to be viewable from a single location?? You'll get more non-competitive interest if people can sit and watch.
Are you thinking of running it at night??? I think you should create a course than can be viewed from a seat and run it on Saturday night or arvo, that could be a main event for the Muster.