[r9etb]

The trouble with ponies is often that they are too little for an adult rider to ride and train them

Technically, it's a "pony" if it's anything under about 14 hands. Harry's already described it as "a small horse," so I think it's probably on the upper range of "pony."

That said, the rest of your points are right on the money.

[tuffydoodle]

"Technically, it's a "pony" if it's anything under about 14 hands."

The Connemara pony, largest of the pony breeds, can be 15h, although not average. They usually aren't larger than 14.2h.