I think athleticism is important up to a point. I'm not super worried about Kinchens though I think the Packers might be. Ignoring the speed and athletic testing has hurt them in not taking guys they should have, but also has burned them when they've ignored the numbers. Amari Rodgers, Josh Jackson and Quentin Rollins are a few examples. I'm sure this keeps GM's and personnel people up at night.
That said I'm not going to say Kinchens lack of speed doesn't bother me at all. You just have to be convinced that all the other stuff he does well makes up for not having top end speed. I'll be reading up more on him from people who know better than me (like Mark) to try and get a better feel for him.
RAS is a nice way to put a simple number to things and it doesn't say it all. Reed is a nice example. His RAS was low because he was regarded as being undersized. He actually ran a 4.45 which is a very solid time.