Brant, I checked mine at the mid range as well (35mm and 50mm). Almost every copy I found it to vary from the short and long end. Most copies stayed close to the 24mm setting through 50mm, then would have a shift at 70mm.
IMO and experience accuracy on the wide end is always bit less on all lenses. But in real life this isn't going to be noticed. You have such a wide DOF at 24mm. I think it is important to know what it is doing at 35mm and 50mm as well.

As with all test, I wash rinse and repeat to make sure I get the same results again. I like to see consistent results every time. If you were a bit off in your testing a second test usually highlights this for you.

I have not heard any clicking in any copy I have. The zoom ring is a bit stiff and not the smoothest but no noise. The focus ring is very smooth and no noise. I am not sure I would like this.

My opinion is this lens shouldn't have to be "broke in", that is just silly. It is a precision device and should work great out of the box. I am not sure I would keep the lens as this would bug me and it just doesn't sound right.