1) What have I wrought?

2) They’re both illegal.

If the authorities had been alerted to what they’d done, Sweetie and her friends would be sent to juvee.

Evidently, Twilight is allowed a certain leeway.

3) At the end of the day, it amounts to the same thing.

4) …

Picture somepony you used to know. Now think about how they might live now; replace information you don’t know with what ifs. Who they might have become, the ponies they’d know, the things they’d do. If they had faults you were aware of, how they would have bettered themselves over time. Think about how it’s your fault you’ll never see them again. How no pony will ever see them again…

Now do that at least once a week for the rest of your life. That’s a fraction of what it’s like.

[Sniff]

Or so I’m told.

5) I’ve stolen more than a few things in my day.

Never stole a bird.

6) Only thing I can think of is rotting horn disease, but that’s not really an accurate analog.

7) Don’t just give me a band; give me a piece or two by them you feel adequately represents their style.

But I’ll answer with The Curse Of Jacques by Grave Digger; one of my favorites by my favorite band.