@MysticMagic One important rule that most people are not aware of is that when I say "farts", I win and the game ends. There is no other way for anybody else to win. Only me.
Nice question. You should ask Lauren. Actually, I think that before FiM all the characters where more equine in the look. Then she redesigned the characters to her like and we got something totally different. She is also the cause of the complete change in direction of the show.
As for the "Horse" part.... it is shown that there exist actual horses IE something bigger than a pony. But it is also shown that Zebras are the same shape and dimension than a pony... so who knows