We did it in Carlisle once. Set up a mini supair field on a basketball court with netting fixed around all of the sides.
Went well untill paintballs started going over the netting anyway since punters shoot up for some reason...
Then we turned it into a shooting range (boring but persuaded people to shoot forward) which was a bigger sucess but definately less fun.
To be honest village fairs are full of kids that are too young and old people, anyone inbetween will either not want to try it or will be drunk. Plus, people are too inexperienced to be that close to other people with markers.
It's a great idea and people do enjoy it but you couldn't do it yourself, there's a lot of effort into it and not that much benefit, if your local site yould do it it'd think that may be a better idea (when we did it we were techincally the 'local' site) and still things didn't go to plan.
I can't remember what happened with the insurance but as it was a site I assume we were covered by the site insurance? Or maybe day insurance.
Overview: Lots of effort, little rewards, and overall a crap boring day where I gave up and went to watch the world cup in the pub
Katxx