Why do LL games if you are not registered as a LL umpire? If they are not going to register you...if they are not going to give you a rule book...I don't care if it's LL or whatever else, don't take the games. Besides not knowing the rules, if you get hurt it's gonna be tough love at the doctor's office because it will likely be YOUR dime.
And as for keeping you from those nightmare situations in LL, a rule book won't be enough if they allow parents to attend games.