Lots of physiological measures will vary - blood pressure is a great example. Throughout the day, even a relaxing one, your BP tends to rise. Also, with weight, you generally are not taking in calories in your sleep but are still burning them, so there is that component too.
No, but I can see where people might think the discs in between the vertebrae could bounce back. They can't, but it's not as stupid as thinking the bones would stretch. Lol
They hype him up with orders from the front office. Gotta sell the player before they can sell the jerseys.
It's possible up to 25. The claim is if puberty was later, 16 instead of 12 that growth can continue later.