Humans

Humans are the most common inhabitant of [the world name that we have not decided]. They are a simple, straightforward race, tending to settle things by means of force rather than diplomacy.

Human Culture
They're stupid and keep killing each other, even though there are plenty of threats that they could unite against. They like to slaughter each other in droves. "Don't group them as one thing". Black humans, white humans, caramel humans, vaguely peppermint humans... I think in general that your difference between humans and elves is that your human is going to try harder, whereas a elf tries to cheat himself out of things and if he can't do that he's kinda screwed. Nothing else to add immediately aside from the fact that humans are responsible for the vast majority of technological advances due to the fact that the other races are either primitive or tend to cheat their way out of things by magic. Humans may or may not be incapable of magic, thus explaining their drive towards technology. Not a fact, simply a possibility. (the black guys have curved swords but I totally didn't put that down.)

Names
It may be useful for other races to have their own word for humans just as the languages of the world have.

Characteristics
Money is a huge factor in the life of a human, it is motivation for them to work and interact with the other races when it includes personal gain and benefits.

Relationship with other races
They believe that the elves are inferior in the way that you would view a selfish brat for the fact that they have basically everything.

They also look down on the Selok-hoth because they are more primative and less philisophically advanced.

There is no general opinion of the Istmelrïl because they have little interaction with them, so they view them as alien and foreign. Feelings are like them meeting talking carpets who have their own ideology and religion and motives and they only way they communicate through calculus and they're making a bunch of plans and you would distrust them even if they were making a grocery list simply for the fact that you don't understand them.

Neurwe are clearly angels.