I like to think I can't control what you do once you have it - i.e. once it's in your possession, it's yours. And if I'm going to spread clones, I don't see why you can't. Besides, maybe you might get something nice for one that I might want!
Yeah it is legit. She was EV training something for me and found a shiny Starly+Kricketot within 10 mins of game time >.> It was about 20-ish hour difference real time between em though. And yeah you can retrade as long as I get the same for the Nincada ;P
You can't actually "un-nickname" it without giving it a new nickname of the actual species. Hilariously, when it evolves, it then keeps the pre-ev species name. Nothing like an Alakazam named "Abra". :D However, I can always AR and change the nickname myself (did that once for a Thundurus when someone didn't want a nickname on it and it wasn't mine); I'll have to nickname it for the actual final ev. and clarify the details to avoid confusion.
Lv.3 Shiny Kricketot is definitely of interest. Legit. I'm assuming, and I also have retrade rights if I want? (I don't get a lot of Shiny requests, I can clone for those that are interested.)