cause they had a firing range in the comics too...they just made sure to have it be far from the camp which they didnt bother explaining in show but could also be the case.

hershel felt the same exact way about the barn zombies in the comics. also, the fact that they turn just from being dead was discovered much later by Rick when he went back to dig up Shane. the show hasn't really explained whether it is going in that direction or not but it wouldn't change hershel's motivations, as it didn't in the comics.

rick knew about shane and lori...i dont think he found out until later but he knew...there was a convo between him and lori when he basically told her that no matter what he was going to raise that baby like it was his.

at this point you should be done comparing the show to the comics though...shane isn't dead so anything that happens involving him is already nothing like the comics. there are also a bunch of new characters that are game changers as well...its not the same thing anymore. it hasn't been since the 3rd or 4th episode of the show.