Moving while striking the ball will affect the accuracy of the shot, but it can used to increase the power of the shot. A forward motion while striking the ball may increase the pace of the shot, but it will make it more difficult to recover to the centre of the court after hitting the ball, especially from the front of the court.
Balance is key when applying weight transfer techniques as it can get players into trouble. Steady the feet as it is necessary to have a wide base of support. If the feet are still moving when the weight transfer occurs, it will make the shot inaccurate, as it will pull the swing out of alignment from the target and prevents a strong recovery out of the shot.
Balance is also thrown of by the lifting of the head as the striking of the ball occurs, this may shift the direction of weight transfer or prevent it completely.
Moving off the ball, or stepping out of your shot too early, (prior to the follow through) will shift the direction of the stroke and attenuate the power of the shot.
Stance and foot position are very important when hitting your targets. Striking the ball when your feet aren't set, cross-legged or in a split will obviously hinder the shot accuracy as well as the recovery to the center court. The speed of recovery will slowly deteriorate and the shot consistency will begin to fail.
Always focus on being balanced when striking by maintaining balance on both the front and back foot (test it out by attempting to swing while having the weight on either leg). It is important to be able to step back towards the center court after striking the ball, as opposed to taking a step forward or stepping into your shot, then turning around and moving back.
Developing the movement and judgement required to strike the ball accurately and then regain balance as well as recover to the center court will come with practice, but players at every level can stand to focus more on setting their feet to hit the ball tighter and with more pace.