"...have shot nearly 4000 images since purchasing the D7000 and i must admit its doesn't seem as easy to get a critically sharp image as with say the 12mp Nikon bodies, I think this is due to the size and amount of pixels on the sensor but after some playing around with settings i have found that by using a faster shutter speed than i would normally get away with sorts the image softness and in fact many people on forums saying that they are having focus problems can be easily cured by using a higher shutter speed and refining your technique "
I completely concur with this finding. You have to be more aware of the shutter speed with the d7k, at longer focal lengths especially, you are NOT going to get away with handholding shots at 1/shutter speed settings or even slightly faster (at shorter focal lengths you can with good technique). Use that high ISO capability and increase the shutter speed.
Most of the examples I see on the web alleging back focusing/ soft image issues either have no image examples or images with EXIF data that shows the photo was taken at shutter speeds that are borderline acceptable in the circumstances for Nikon's previous generation 12 MP sensor.
I am sure like every camera model on the market that the d7k has some duds out there, but by and large these are almost certainly rare.
The hot pixel issue is an interesting one. It is certainly not surprising to see hot pixels in HD video shot on a DSLR analog sensor at high ISOs. It is more problematic when they are appearing at low ISOs or in unacceptable quantities. Canon has been dealing with this for a few years now and has not completely fixed the problem. I will be interested to see if Nikon does. It is odd that if this is a problem inherent to the camera that some people have it and some people do not. This might be a product of the numerous variables that go into hot pixels forming.