Hey Slicepong, we are doing ok thank you and trying to stay busy, we hope you are good too! Yes the closed bat angle is important for getting both spin and power and the wrist is a big part of that. When you bring the bat back on the backswing the bat angle should already be closed so then you can just swing through the shot with confidence and not worry about changing the angle during the backswing or the shot.
The relaxed arm and letting the body and legs do the work will help for sure, it seems to me like you just need to keep that consistent bat angle and get confident with the timing point of striking the ball with this bat angle, getting it at the top of the bounce and you should find you can get more power.
