Ok, haven't been around much. I'll work on another version soon. My thoughts:

Yeah, Unicorns and Pegasi probably need to be toned down a little bit.

About object manipulation, I think that's best left to the territory of roleplaying. D&D doesn't model some parts of behavior in very high detail, such as being left-handed vs right-handed, and I honestly think for the sake of simplicity and playability we should just ignore how ponies are able to competently handle objects.

About teleporting, if we're going by the current show, only Twilight, Celestia, and Luna seem to be able to do it. They are probably moderately high level Sorcerers who know Dimension Door.

And hmmm, I don't know if Zebras really need separate stats from the Earth Ponies. Zecora doesn't seem very different physically and we don't see any others to try to establish any kind of baseline as to whether they've got any particular leaning mentally or anything.