gotta agree with everyone above, its not easy work, and with every jobs you get idiots, its just unfortunate these idiots have markers. but dont get angry and be patient that way you can enjoy the good parts of the job like most of the people who go there, and normaly the other marshals are a good laff.
qualities:
*patience (quite alot sometimes)
*knoweledge (of equipment/rule's etc)
*the abiltiy to know how to treat different people
*Out going
*fit and not adverse to pain
and a tip from me, have fun the players will respect you more for it, and if they do something wrong, tell them why its wrong, more people will listen then. for example after a game a lot of people seem to enjoy dry firing markers, the times when ive explained that this isnt wise because each bottle has to be refilled 3-4 times a day and the more time we spend on refilling the less time they have playing, plus its a pain in the posterior, most people listen. oh and aviod the temptation to get even, most people are pumped up on adrenaline during paintball so things can escalate very quickly.