RWBY is an alternate universe where the Earth suffered an apocalypse and mutated the humans to have aura and semblance....and the most affected have animal parts attached to their body. The vengeful ghosts of the animals that died in the apocalypse have returned to the living world as monsters known as Grimm.
The maidens are a metaphor for the four girls who have undergone human experimentation and the old man was a scientist who has already achieved immortality but was disheartened due to his friends dying around him.
The war between the Faunus and humans was actually a slave rebellion. Faunus were originally slaves and they were treated very poorly by their owners. One of the many slave owners founded the Schnee Dust Company and built it on a Faunus grave where he used to hide his executed bodies of his slaves.
Salem was originally a human who existed pre-apocalypse and was also affected by the mutation. However, she was killed because she was seen as a supernatural being. Her spirit was enraged over her murder from the same species she once was, and vowed revenge against all of humanity. Thus, her spirit returned as a humanoid Grimm, and secretly planned for the downfall of all humans.
Crazy theories at their best.
Jaune is French for "Yellow".
Yellow is the color of the Sun.
The Sun represents mornings or in other cases, the season of summer.
Jaune's emblem looks like a sunrise.
Jaune is the true Summer Maiden.
Jaune = Summer
Jaune × Jaune
= The true ship of RWBY