I feel it's malicious to play a prank, but I wouldn't say every person who does a prank is evil.
I touched on it below, but loving someone could definitely a form of compassion.2. I think you've confused kindness with compassion. Kindness isn't necessarily good or evil. An evil person understands the value of kindness, so far as it extends to loyalty from those being treated kindly. Compassion, on the other hand, requires empathy for the plight of others, which stands directly in opposition with the total selfishness of evil. A kind person will donate to a cause and feel good about the donation. A compassionate person will donate and feel guilty that they were unable to help more.
Well, like I said, love isn't inherently anything, it's just another facet of a character.3. I'm just going to quote myself on love here. Love cannot be evil. If the love appears to be evil, then it is not love, but some other emotion, whether it be pity, or lust, or pride, etc., masquerading as love.
I mean, Nale and Sabine, among some of the most evilest characters in the comic, genuinely love each other (and not just a form of pity/lust/pride). Hilgya is surely not pitying her son either.