The whole D7000 backfocusing issue is a hot topic on most forums, so I'll try and keep this objective. I was experiencing similar issues with my D7000, and the trend was that wider lenses had more of an issue than midrange and telephotos. I sent mine in for repair because I could not fine tune the body enough to get in-focus pictures with my 20-35mm f2.8. I sent it to Authorized Camera Service since I have a grey-market body, and the AF is perfect now (controlled testing with FoCal software/45deg charts, and actual photography).
I would recommend sending it in for repair/calibration. I'm very glad I did with mine.