I think it's also important that the group only consists of families (not counting Strand, who we know nothing about). People who want to protect their family or lost them can be among the most dangerous people. Rick, Shane, Carol, Governor, Morgan, Abraham (judging from flashback); all of them are heavily effected by either loss or the will to protect (with Carol seeing the entire group as family).

Now you got three families, two of which are connected by the relationship of their parents. We already saw that Daniel & Madison were willing to go the extra mile for their families and by the end of season 1, so was Travis. Like you said, they pretty much did not care how many people would die because of them. Their neighborhood, the military base and also countless of people who will die because of the 2000 zombies they set free into the world. So they are willing to do everything, as long as it keeps their family safe.

It also doesn't help that they already had countless of bad experiences in this new world. For example the government/military lying to them and taking people away, even killing many who didn't want to evacuate. Alicia & Chris also encountered those rapey soldiers in the season finale, who also beat Chris up for being protective of his step sister. Travis was betrayed by the soldier he set free, who then shot Ofelia. Not to forget that they already saw what people are able to do during the riots.

I'm really curious what lies ahead of them and what else they are willing to do. Seems like with Strand, they got another person who sure as hell won't be a moral compass and it looks like Travis also kind of lost it. Except for Nick, the children seem to be the most innocent, but Chris & Alicia are easily influenced due to their age and Ofelia already lost her mother and got shot by her former boyfriend. Don't think they will keep the group on the good side.