i see that you hit little bit like roddick. i dont know how hard your groundies are but if you want to hit a very hard fast pace shot, i make most of my core. The most important in tennis is your core, your core is strong you build pace in your shots. so like if your going to hit a top spin forehand it is crucial in todays game that you must leave the ground, that will give you the most freedom to your muscles and esp your core equaling harder shots. thats just for power but your footwork needs to be fixed. i dont know if you have heard of snakes or some call them lines, you must do those that will fix your movement because that will train you to stop and run on a dime. other than that just start moving more precisely and you will be very good. your very good now but i always seek to be better so i will give you the same advice.
Current racquets- kFactor SixOne Tour 90, nCode SixOne Tour 90 ps, (2) Blx Blade tour 93, Prince Exo3 Tour 16x18