I wouldn't say he CANT feel feelings, there are just some he can not grasp. He seems to be a almost sentient AI. He never gets upset, he just rationalizes things. He picked Charlie based on Charlie's attitude towards him, you could call it "jealousy" but he was instructed to "try harder" so he calculated who would be the best choice and went with Charlie.
It is kind of strange that a military facility has no...guns...of any kind. Maybe it was more a laboratory and the military guys got the fuck out and left the lab rats to die in the building.