Everything I've seen on him tells me he would be fucking amazing at Everton - or anywhere.
Everything I've seen on him tells me he's not going to leave Celtic for Everton - or anywhere.
I personally think that if this lad does go in the next few seasons, while he's still young - he'll probably set the world record transfer fee for a defender. For two reasons:
He's fucking brilliant
It would take an obscene amount of money to get him and Celtic to agree to it