Darth Maul is not the first non-human force user in Star Wars, Yoda is. A double bladed lightsaber is just two attached at the hilt. Darth Maul was more a pawn than Grievous, he only kills one Jedi, Grievous kills more than that, lays seige to Coruscant, abduct Palpatine, Kills the Jedi escorting him, ect..
Vos survives, although the comic shows otherwise, because in another story he meets a young Han Solo, looking for treasure, He minds trick Han into forgetting him. But I thought he turns to the dark side, he looks quite light in this comic, although slightly insane