"Emotion" is a complicated subject. One thing that snakes most likely do not have is social attachments the way that mammals and birds (that care for their young, live in social groups, etc) do. But I think it's also an oversimplification to think that they feel only hunger, thirst, pain, heat, cold, fear, and security (being basically the lack of any of those other things). Some are more inquisitive about their world than others. Some are more risk-averse than others.
I think they can definitely tell when you're looking at them - and if they're feeling even the slightest bit insecure, they don't like being stared at. It does make sense: if you're a snake in the wild, the only reasons an animal bigger than you would be staring at you is if it's deciding whether to eat you, swipe at you, drive you away from its nest, etc. Much safer to go unnoticed.

My story about snakes being smart is that my BP's cage sits in the living room, in the same place that my old corn snake's cage was. The corn snake lived in that spot for ten years, and had a variety of hides and boxes and tubes and stuff during that time, but he usually liked to hang out with his head facing the corner of his cage that would let him watch the living room door. I got the BP when the corn snake died, so his cage is in the same spot. And if he's awake and sticking his head out, he always hangs out facing that door, especially when he's hungry. When I take him out, he always heads toward that door, no matter where he is in the living room. And the longer it's been since his last meal, the harder he tries to go that way.
My theory is that both of them figured out that food comes from that door. And I think the BP has learned to recognize the metal bowl I usually use to thaw rats in, too.

But I think we should be careful how much logic we ascribe to them. If a snake is terrified while being handled, but doesn't actually get hurt, it doesn't go home thinking "well, that turne out OK because nothing bad actually happened". It just associates the whole business with being terrified. Actually, we humans are that way too, we just don't like to admit it. If you're afraid of flying and you have a flight with a lot of turbulence but the plane doesn't crash, you don't go home thinking "Nothing bad happened, so I won't be scared next time"; you go home thinking about how terrified you were and you dread the next flight that much more. Or you drive instead, even though it is an easily demonstrable fact that your actual risk of getting hurt is exponentially higher if you drive than if you fly.

It's something to keep in mind, anyway. If handling is always a terrifying experience, the snake is going to have a hard time learning that there's nothing to be afraid of.