Well, it's up to you (although you are being way too OCD for a mass produced product) but I would just wait for things to go wrong since you have a warranty and you SHOULD buy Applecare. We all love our Apple products and everything they make is beautiful to look at (I have a Macbook Air and love it) but you have to be honest with yourself, would you be/have you ever been this anal from the purchase of a Windows PC? I'm betting, NO. It really has nothing to do with price.
For me, I never gave any of my PC's a second look after turning them on. Once I started "using" them I could care less of any imperfections.
You will be the same way once you really start USING your Mac rather than look at it like a pretty decoration. Remember, you bought it as a tool and not to pretty up your house.
Not trying to be harsh but let those things go and enjoy your new Mac. After a few weeks and the honeymoon is over you won't care how perfect it is, you will most likely scratch it anyway from normal use.
And yes, DO NOT EXCHANGE IT, YOU MAY GET A DEAD PIXEL, and Apple may not exchange it for that and that would royally annoy more more than slight imperfections.