Where was it that T-Dog was trying to lead Carol to? Was it the boiler room? If it was, I wouldn't be surprised if Carol is there tending to Laurie, who is still alive, and Carol had Carl fire off a decoy shot so that people wouldn't risk themselves to come rescue them. That would explain why Carl is handling her 'death' so much better than Rick is (of course, I also am wondering if Carl isn't becoming a little sociopath-in-training).
I was also wondering why they didn't put a bullet in T-Dog's skull as they went by.
It's a foregone conclusion that Axel and Oscar will join the group. If nothing else, from a storytelling standpoint, they need a new mechanic.
I have not read the comics, so I don't know if this is in it or not, but . . .
They either have a warehouse full of golf balls, or that's a one-and-done kind of hobby to have.