I disagree. You do have to go through with something like killing Tamora, if it makes sense and it's a situation the character has been put in. Now, I could have maybe set the situation itself up differently, but I had limited control over that because people who I didn't control were involved (like you, Luke, and Tara). Ossanlin literally dumped Tamora at Terenia's feet and said "deal with her." Terenia's personality at that point in her life didn't allow for any other option. Giving Tamora another chance would have been completely OOC.
Now, admittedly, that's changed since then. Being with the rebellion has stabilized her quite a bit, and she might, if put in the situation again, let Tamora live. But at that point in her life it was literally the only thing she thought she could do while maintaining her belief structure.
As for what Claxter did and didn't do, then perhaps Terenia and Corliss should be dead, or at least Claxter should have made an attempt on their life. But they aren't, because (I assume) Claxter was uncertain enough about his surroundings to restrain himself. You've already played him off as a somewhat cowardly person, at least initially. That's why he ran from the war to begin with. It would make sense then that he would be reluctant to kill someone in cold blood, even if they are doing something he finds morally reprehensible.
Just because Terenia is "human" and Claxter is "Andalite" and Keslin is "Yeerk", that does not mean they behave in certain ways. Those are factors that influence their personalities, but they do not define it. Not all Andalites will kill a Yeerk on sight. Not all Yeerks will infest someone involuntarily. Those are the same sweeping generalizations that get Efaen into trouble.
