No not really as they come from two different countries. although they both do eat grass, just not the same kinds of grass.
You groom a mustang the same way you would groom any other horse.
A Mustang horse and the Stallion horse are in the same family group because the Mustang is a breed of a horse/pony and a Stallion is simply a male horse that sometimes gets geldied after that they are called Geldings not a stallion. In other words when male horses are stallions when they are born.
Mustang horses are born same way as a domestic horse except the babies are born with no protection from predators.
The word Mustang is not in the Spanish vocabulary, it would be used the same as in English, except it would be pronounced differently. A mustang is a horse, the Spanish word for horse is "caballo".
About 5 Wheel Horse Power. Same as today!
mustangs have the same type of teeth as any horse.
The same type of teeth as a tame horse.
Quite often, yes.
The same as any other horse mainly, they are strong and have powerful hindguarters. They have more of a wild instinct in them though.
You can take care of it the same way you do as the other horses. There is no difference with Mustangs.
Same kingdom.
Well, it depends on the horse. No two horses are the same, including Mustangs. I know a Mustang mix that is calm as ever, but some can be really wild. All horses are different and amazing in their own ways.