You have to find a way to get Ryder back.
As for the openers, Watling is one but you can't leave McCullum there. You can't put a price on getting to lunch day 1 none down. McCullum is too aggressive and gives it away too easily. That's why I'm a fan of someone like Hamish Rutherford. Guys like Watling and Rutherford can grind out a start.
If you have McCullum-Taylor-Ryder-Williamson at 3-6 then you've got the runs you need if Watling and Rutherford can blunt the new ball. You also have a counter-attacker in Ronchi coming in at 7.
As for the spinner, how did Todd Astle look in Sri Lanka? He can bat too and fills the numbe 8 spot. Other than the you're almost better off playing four quicks and using Williamson unless you're on a raging turner.
Bracewell needs to go back to the Plunkett Shield and learn how to pitch it up. He's not quick enough to bowl as short as he does. Is Mark Gillespie fit yet? You need someone with a bit of venom. I like Trent Boult but he's flat out getting it to 130kph and doesn't have the control to do that. Wagner and Southee should share the new ball in my opinion.
All of this is band aid stuff though. Serious changes at all levels need to be made otherwise we'll be back here five years from now saying the same stuff over again.