1) First, you can observe animal behavior - if they tend to help other animals without a clear reward for themselves (such as in the case of dolphins), you can conclude them to have compassion.

Second, compassion in humans can be verified in the brain - where the observation of another being experiencing something (say, painful) is accompanied by the activation of the same regions that are also activated when the subject experiences said thing himself.
Don't know whether they've done that with animals, but that would be a way to go on without knowing what it's like to be a bat.

2) I asked whether I would be justified to think that, not what some stupid backward superstitious cultures "thought".
The point being, we don't like a lot of things, but calling someone "evil" (I mean in the real sense, not the "he has evil eyes" kind) requires some kind of infliction of pain and suffering, i.e. a strongly negative personal experience on someone else.

Reminds me when the Amazing Atheist once said something to the effect of "evil is whatever stands in the way of my/your perfect" world, and I was screaming at the screen... lol.

3) Now that's just silly.
An olive has no personality at all. Bacteria or insects could be described as "programmed biological mechanisms". Advanced animals such as killer whales / dolphins, or primates, or cats'n'dogs, already resemble too many typically human displays of individuality and personality, and WE EVOLVED FROM THEM.

One dog is peaceful and non-aggressive, another will bite out your guts if left off the leash, unprovoked - but nvm that, they're like two olives.

...

4) In that sense, yea, if you wanna define good and evil on a purely intellectual basis, then yes.
But we don't put this limit on humans (some aggressive psychopath who happens to have no conception of "ethics" and just acts on his drives is still evil in our books), so why do that with animals?