Looks fine to me. An address is just a number, this one being hex encoded.
Okay. In my experience "the address of x" is taken to be synonymous with "&x", but I suppose that's a pedantic difference.
arr is an array. So printing arr[0] would print the contents within the first position of arr, and &arr[0] would print its address. However if you simply print arr, then that's not the contents of the array, so it will print the address. &arr[0] should print the same as arr.