The Bow asset was created in the JPG format by default. You can easily convert it yourself however, using most editing programs. I have no intention of recreating the boarder anytime soon, for there are still lots of maps that need to be redone, however you're free to update the graphic yourself using the provided assets.
Also, you want to be sure that the run key is set to Toggle and not Hold in the options menu, also make sure that the Turbo speed is turned off, you shouldn't have issues with lining your character up if it were off as intended. Press the Alt key on your keyboard to turn the turbo speed on and off.