Kaikoura may not be back up and running after yesterdays earthquake. Christchurch provides a half days worth of activities, but can serve as a base for some nice places in the surrounding areas (especially Akaroa). Queenstown itself is nothing special, the activities around it are. (I didn't find it "cool" in any way, perhaps overrun by Asian and American tour groups.) Consider driving from Christchurch down to Queenstown. The drive is stunning, and you can spend a night or two at Mount Cook, and also stop at Lake Tekapo and/or Wanaka. Given how much time you have, you can basically make a loop of Christchurch to Mt cook and down to Queenstown, side trips to Fiordland, then down to Invercargill, then back up the East coast.

If you leave in and out of CHC, I'd skip Auckland, and maybe the entire North Island. I enjoyed Wellington, and if you're a city person it's the nicest city in NZ, but if you're not, it's not worth the travel if you want to get in deep with nature.

An alternative tour would be driving as I mentioned above, from Christchurch to Mt Cook to Queenstown to Invercargill and/or Dunedin, then flying up to Wellington, taking the ferry back to the South Island and hitting the Northeast coast on the way back to Christchurch.