Yes, that is the guy I am talking about. They have only mentioned his name a few times on the show and I only know it because a Youtuber I watch says it a lot, so it has been pounded into my head otherwise I would be in the same boat as you and just call him that attractive guy.

The reason they are keeping Bob alive rather than just outright killing him at once makes sense actually. Back in Terminus they had a way to preserve the bodies so they could kill them at once, hence the meat hooks and I assume they had a generator for refrigeration, but I could be wrong. There they treated people sort of like we do cattle and they were able to avoid the whole breaking of a person's mind while they ate them; in a VERY odd way it was humane. However, now that they are out on the road they have no way to preserve the meat and the only way to keep it "good" is to keep their victim alive and slowly remove parts. They are not keeping him alive to torture him...well, hmm....that might be where the comics and the show blur for me because in the comics there was no Terminus and the people Gareth and his group were based off were always on the road. (Sorry for bringing in the comics again, but I kind of have to in order to explain myself here) So I can't say for sure that Gareth isn't keeping Bob alive as a form of torture, but I don't think so and I am pretty sure that it is because there is no other way to keep the meat fresh.

I am not AT ALL trying to tell you that Gareth is a good guy, he eats people for crying out loud, but I what I am saying is that he is not this wholly evil guy that is just doing this because it is fun. Gareth...has been through a lot when the world went down the crapper. He had started a safe haven and a group of thugs came in, captured his people, raped the women and children and just slaughtered pretty much everyone (this was all hinted at in the first episode just in case you might have missed it). He had to sit back and watch as his mother was taken repeatedly to be beaten and raped by these people and it is no wonder that after a while he would start to lose his mind a bit. They had to get out from the grasp of these thugs and that ended up being by eating people, which is a thought process I don't think he entered into lightly. I don't know how his group got out of the train car we saw them in in the first episode flashbacks, but I assume it is a bit similar to how Rick's group were planning to get out.

When Gareth tells Bob that he tastes good...well, obviously Gareth is not right in the head anymore and you can just take that as something a person who has or is losing their mind would say. I never claimed that Gareth was sane, no one that decides to eat people even when backed into a corner is and there have been studies that show cannibalism does tend to mess with your mind in bad ways. There is some sanity left in him, I can see it in the way he talks sometimes, but not very much. And now that I think about it more I think when he says that they don't enjoy eating people, at least for himself, I think now he is just trying to convince himself that he doesn't enjoy it. For however long they have been doing this I think some part of him might have come to enjoy it, but he doesn't want to admit that he has.

The show is conveying this whole thing perfectly honestly. Eating a person is going to be part torture, there is no getting around that even if there hadn't been a speech at all. What the show wants you to see from Gareth's words is that the choice to eat people was one they needed to make in order to survive and the choice to keep Bob alive and slowly kill him rather than killing him quickly like they had intended to do back at Terminus(remember the big metal thing they were kneeling in front of?) was something they hadn't wanted to do either. They part chose to keep Bob alive and remove his parts over time because, like I said, there is no way to preserve the meat out on the road and as part revenge for Bob's people destroying Terminus. If this happened in real life there would be this giant grey area for methods in which people would use in order to survive, nothing would be as clear cut as it is now and the show is portraying that perfectly.

It confirms a theory I read that Sasha is the show's version of where Andrea is at in the comics and that means Bob has taken over Dale's position, which is not good at all for Bob. And for those who did not understand why Bob was crying and leaving the church it was because when that Walker had pulled him down he got infected and he was leaving to either take care of it himself or so he would not be around to hurt the others...I forget which. If you want to know more just look up the Hunters in the Walking Dead wiki or read issue...11 I think it is.