Quote: "Ok i just heard that they can hurt each other with the bazooka "
That is true. Since the bazooka is an explosive weapon, the explosion, not the weappon, will damage characters.
Quote: "and thought you could give them modified versions of guns that where explosive but it sounds like the guy who said it made a mistake sorry"
You were the guy who said that.
Quote: "is there any script which will give the player 1 health every 5 seconds which you could give to a trigger zone and strech it across the whole of your level "
It's easy enough to make, but not a good idea. Any other script which used a timer would not work properly, and it would be a memory hog.
Best.