I don't think "good but misunderstood" is a good phrase to describe Loki at all.
It's more that he's got a lot of potential that can go in either direction, and he's very easily guided in either direction by emotions. He's very much a villain originally because he was guided by jealousy and greed and so on, and the point is he could have easily been steered in the opposite direction. He's not inherently good or evil, he's open to both and just responds well to the right nudge.