This has been going on in the game since 1.0
there is always a slight delay when turning and looking on the 360. are the devs aware of this and is there any way to fix it.

Its probably your controller, because I have no sensitivity problems with my 3 xbox pads.

I had some problems that were most apparent in Skyrim for some reason that basically my character would sometimes just stop.
Menu's would also be laggy to open, I'd have to hold it for about a second or two or select it a couple of times for it to work.

As it turns out it was my controller. Buying a new one fixed it. If all the stiffness is gone in the sticks from use over the years than it's definitely your controller.

Invite a friend over, if you can, that has an xbox controller just to make sure that's the problem before buying a new one though, just to be sure.