The vinegaroon is not an insect at all, but rather an arachnid, one of the Uropygae (the name is typically applied to members of the genus Mastigoproctus). It's a relative of the better-known spiders, harvestmen, scorpions, solpugids and mites, and indeed looks rather like a scorpion. However, instead of the typical scorpion tail, tipped in a venomous sting, the vinegaroon has a long, thin whiplike tail. This leads to its other name, the whip scorpion. This is not the same beastie as a whip spider, which is a nickname for a completely different arachnid.
As noted above, the vinegaroon's primary defense is a mist of acetic acid. While this is basically useless on people, it's quite irritating, and even slightly poisonous to many arthropods, and distasteful to birds. Besides this, vinegaroons can pinch with their pedipalps, much the way a scorpion can. While this can be painful, there's no venom involved.