Happy as a little lark! Singing to the snow is so cute. 
I have heard that but is this true even before the first molt? "he" is 12 weeks (and yes he is a normal split to pied)I can't tell the mutation properly from the video Jill but he appears to be a normal. But normal colours are easy to sex even as babies. If you look under the wings a normal female will have spots all the way up to the equivalent of our armpit and a male will only have spots halfway up. This applies to any normal mutations regardless, normal grey, normal cinnamon, normal whiteface, normal platinum etc. Of course after the adult moult the face colour comes in.
This is very interesting, Kate!In Cockatiels Pied is a Recessive Gene so if one parent is Pied then about 50% of the offspring will be carrying pied if I remember my genetics correctly, I think sometimes it is also called semi dominant. But I know I am right about the sex linked genes. In my mind it is probably the easiest to remember. Many breeders don't put 2 sex linked birds together so as to make it easier to sex the offspring. That is unless they want sex linked males. But saying that they will breed 2 cinnamon's together so that all the babies of both sexes will be cinnamon. But because of some bad genetic traits it is not wise to breed albino to albino or lutino to lutino. Bald patches is probably one of the main reasons. It has to do with the way they were originally bred so that people could get more money from them. I know when the Lutino first came about in Australia they were worth about $5000 each and the same with the Albino. People invested lots of money in the original stock so they wanted to recoup their money quickly. Also they were trying to breed the palest Lutino's together in the hope of getting a nearly white bird, it didn't work. It wasn't until the Whitefaced was bred that is was possible to get the white bird they wanted. A good Lutino should be a bright buttercup yellow. It is also possible to get what is called 100% pied, which is a buttercup yellow bird with black eyes and not the red of the lutino. It may have one or two grey feathers. It is also called a Reverse Pied. Very hard to pick from a Lutino unless you shine a light into they eyes.
Personally I find genetics fascinating, but so many breeders just seem to shut down when the word genetics is mentioned.