I'm not sure you noticed. But in the episode when Discord "lies" you put it to Mane Six, he infact uses his powers to "corrupt" the in a way so they become opposites. It's evident seeing as the colour drains from them. Discord isn't a malicious being like Ruin, he just likes it when people don't work well together. Oh, and Discord doesn't make them fight amongst each other with lies, he uses illusions and enhances the bad qualities in people. Sunset Shimmer on the other hand, disbanded Mane 6's human counterparts with lies. and randomness IS chaos.
As for Celestia, I guess your right, And I meant that Amity and Hope may be 2 different Shards residing on the same Shardworld (at least for now)
Amity would need a counterpart as it is part of the natural order of things. Endowment didn't because it never Physically do anything to the world. Ruin needs Preservation, Dominion needs Devotion
Ah, but the Earth in MLP is considerably different than our world. I will let you find out more about it then u can make ur arguments seeing as your not focusing on the movies. BTW the Mane 6 counterparts use magic to defeat Sunset Shimmer so there IS magic on that Earth.
As for Pinky Pie, Why not a family of Worldhoppers? As for Twi, she is definitely in her adolescence seeing as she has already been to school and all not to mention ponies age differently than us. And Pinky could have come from another Shardworld where everything ages slower.
BTW I am incorporating G1 and everything after