I think James thought about kicking ass. At least kicking Scott's ass. But then she realized what kind of guy Scott is, and figured he wasn't worth it. But she saw that Chloe has feelings for Scott (or at least Chloe thinks she has feelings for Scott), and was the bigger person and let her know what was going on. Sort of giving her Scott.
And Chloe had every right to be angry about the idea of leaving Scott behind. The person you're involved with could die, you're gonna speak up. Of course, the others had every right to just ignore her and do what's best for the crew. she has no authority so, other then letting her vent, they don't have to listen to her. Which they really didn't.
Basically, I think Chloe is just trying to fill the void and feel good, even for a moment. She's hooking up with Scott so she doesn't have to deal with the loss of her dad and being trapped on Destiny. And that's a pretty normal thing to do for a lot of people. Scott's taking advantage of the situation, and is might also avoiding dealing with the feelings and memories dredged up during the desert planet.
The only characters that bug me beside the scientists (who are supposed to bug us with their ironic stupidity when dealing with survival situations) are Chloe and Scott. But only when they're together. Separate, I don't mind them. I'm waiting for the situation when someone realizes that she's a senator's aide, and probably the only one on board with any kind of actual political experience. Maybe some kind of diplomatic situation with aliens? Or having to work with the IOC? Until then, she's a fish out of water. She has no other skills to provide since she really didn't belong there. She was only on the base for a political visit. Until they start training her and making her pull her weight, that's what she's going to be.
Greer is quickly becoming one of my favorites. He's a badass, but he's a badass with principles. He, Young, and Rush are at the top of my list. With TJ and Eli right behind them.