1: Do you think Alicorns are long lived or immortal?
No, I think they just have a longer lifespan than the more common species of ponies.
2: Do you think Celestia and Luna have siblings? If so how many?
No, I don't think so.
3: Do you think they have parents?
They must.
4: Do think alicorn is a seperate kind of ponies? Or just simply a pegasus unicorn caused by some genectic happening.
Yeah, I believe it would be a seperate kind of ponies. Or maybe unicorns are simply earth ponies with a strange magical growth caused by some genetic blip stuck on their foreheads. Heck, I don't know.
5: What's your take on the alicorn hair? (LOL)
I honestly don't really like it. I liked luna's hair better in season one when it wasn't all.....plasma-like.
6: Celestia's hair was pink? Well in the pilot she had pink hair when banishing Nightmare Moon and then in the stained glass when she and Luna defeated discord she had blue hair.
Magic. Clairol. Who knows?