My rank and stats ARE MY LIFE!

play the game, have some fun. If you want to brag about stats and rank then make a maccaroni posterboard and have your mom put it on the fridge. Take a picture of it and put it on your facebook and have all your friends 'like' it and comment on how well you are doing and how hard you must have worked to get such good numbers. Then when it comes time for you to get a job then you can submit the same maccaroni posterboard of your stats and ranks and use it as professional credentials that will put you above the rest of the other applicants.

TL;DR?
Play, have fun, you don't get any special rewards for doing good or bad.