The key to a bunker shot is to eject the sand from the bunker and have the ball go with the sand
A great visual drill to fix an outside in swing path is to place a string on the ground to represent the target line and place a head cover just outside of the line, this will visually help you keep the club inside on the downswing so that you do not hit the head cover
Flexibility as you get older is very important, it lets you wind up your body to hit the ball with more power, and swinging a pole can help you do this as well as fix your release point