Oh, and you may want to look up
xenophobia. It's exactly what you're displaying: "the perception that not only is it impossible for certain people designated as foreign to integrate into one's own society but also that they pose a threat to the integrity of that society."
Okay, this is entirely about you believing that the Velkar could be like "genetically" evil, and humans are genetically good?
Evil is not genes, chaos is not genes, tyranny is not genes.
I believe there is a tiny, tiny, barely worth mentioning chance the Vellkar could indeed be "genetically evil" - or more accurately, genetically predisposed to behaviors we would find evil or dangerous to us. I don't find this likely, it contradicts what we've seen of them so far. But the fact is that we haven't seen a lot of them yet, so it doesn't hurt to have Victan spend a year or two looking at their society and checking.
You recall my very first post on the issue, that aliens should not be looked at as if they were just different human cultures or ethnicities? Because when we're dealing with members of the same species (or Star Trek style forehead aliens) I totally agree that evil is not genes, chaos is not genes, tyranny is not genes.
But the same is not necessarily true when dealing with other species. A tiger is in fact genetically predisposed to kill and eat you, if you're more or less prey-shaped and behaving like prey.
I see absolutely no reason why an intelligent alien species couldn't have evolved to be genetically predisposed towards behaviors we would identify as evil. I also see absolutely no reason why they couldn't have evolved to be much nicer people than humans.
But we won't know until we check. And every new alien species is potentially different from the last.
Xenophobia evolved because if encountering something foreign in the wilds, the consequences of incorrectly assuming it's friendly are usually much deadlier than the consequences of incorrectly assuming it's a threat.
Within the context of human civilization, that instinct almost always leads us astray if we listen to it. Within the context of running into an unknown animal of sufficient size and physical capability somewhere in the wilds, it's absolutely the correct response.
When dealing with intelligent aliens whose exact nature is as of yet unknown, we shouldn't trust the xenophobic instinct. But neither should we automatically assume there is no threat. Aliens aren't human, the assumptions we can usually rely on when interacting with humans do not necessarily apply here.
The solution is to employ reason, be cautious but not aggressive, and gather information until the unknown becomes a known.
With the Vellkar we're already reasonably close to that point, but I'd like to dot the i's and cross the t's.