Barrel vings are most certainly not safe, i have seen them blown out of guns on many occasions. I also think that air tanks should have a quick inspection before they can be filled (some events don't bother), air filters should be on ALL filling stations, i have had to, on more than one occasion, open up my reg & seperate it from the bottle to get a load of mud and sh*t out of it.
There should also be proper proceedings for those who lose barrel bungs/ bags on the feild, i've done it a coupla times. I think barrel should be removed, along with the bolt and hopper.
Most of the google safety and stuff is doe by players really, because most refs are marshalling games, and there is really no preblem here, because everyone is really very vigilant, but i still think that a set of rules regarding safety should be made available to/ given to teams vefore a tourney