I don't think he should move from five, for me. his is an exhausting job and the recovery time between fielding and having to strap on the Mums and Dads is important.
Sorry mate, don't agree with that; plenty of skippers have opened successfully, which is the extreme example of no recovery time.
Yes, if he was playing in a great line up he could dictate where he bats. But he isn't - Warner, Cowan, Hughes is a potentially fallible top three, Watson should be at six and whoever they bring in (Khawaja?) will need time to get used to Test cricket. He should lead from the front and say "look guys, I'd prefer to bat five but the team needs me to bat higher..."