Orcs are intelligent in that they can build things, and have societies and are able to communicate amongst one another. But they are also highly aggressive and carnivorous, and consume the flesh of humans as well as animals, so it can be assumed that they generally don't get along well with humans. I'm not going to give a definite 'no' to other fantasy races, but it can be assumed that they are generally rare or hidden- not for general play.

The closest equivalent to 'Dragons' would be Wyverns, and yes, there are indeed Wyvern Riders- a integral part of the Varyan army. Demons and other D&D or fantasy style monsters also exist in the world, and are essentially integrated into the world. Such creatures are generally accepted as a facet of wildlife, similar to something like wolves- though admittedly much more dangerous than wolves.

That being said, Monster/Demon Hunter is a valid- if not highly dangerous and uncommon, profession.