No. Your rank or promotions are not tied to your physical fitness scores, at least not directly. Your score is recorded and will be reflected on your evaluation reports, but a top score can't make achieve rank faster. It can, however, keep you out of trouble. It might keep you from extra duties that no one else likes. It will depend on the unit, the commanding officer, the platoon sergeant, etc. If you score low, they can make your life hell on earth, so always try for the best possible score.
For doing what the f*ck you are supposed to be doing? Look kid..the military is the adult world. You don't get gold stars for doing what you are paid to do or simply "trying your best sweety"
You f*cking kids kill me...you wonder why everyone makes fun of your generation...