You are looking at a few actions, and yes ones that either are or lean evil. Their characters are more than that and they do plenty of good things too. Letting enemies go (or in this case potential enemies) is not one of them.
You can't take this as a whole. For example, I doubt anyone would call Cattie Brie from the Drizzt novels "evil", yet in one of the novels she states that Goblin children should be slaughtered in their nursery without mercy and Bruenner (her also good father) agrees with her. I think that act is undeniably evil even though both of those characters as presented in the novels are undeniably good.
I don't like Chaotic neutral characters in general because I think this is the most difficult alignment to play, but I also don't think these characters actions as a whole are necessarily evil. Chaotic, absolutely.
1. They do lie often and have no use for the truth (chaotic)
2. they do kill prisoners rather than release them (evil) but they refuse to torture prisoners for information (good)
3 they do tend to err on the side of caution instead of rightousness - better safe than sorry - when it comes to potential threats (neutral?)
4 They never steal and give to charity (good)
5. They deal and work with both good and evil factions to get the job done (neutral). One works with the harpers, the other actually joined the Zhents. The Paladin is unaware of both factions, but the CN PCs are aware of each other and they use the factions but have no real care for advancing their goals nor any value in the allegiance other than its usefulness. (Chaotic).
6. What they do is always for the greater good of society albeit often motivated by the reward they will receive (neutral)
I think overall that is pretty neutral on the good-evil scale.