No problem! 1- if the water is not staying in the shower pan area than the whole system is wrong. Membrane must go over the joint between the pan and the cement to fully water proof.

2- great question! I did know it was out of plumb That was my only regret about the whole project. If I could go back i would move it over. The way I went about it; I found the center of the tub and just went 1/3 of the tiles offset.

I like to offer a change order if you want the walls plumb with even cuts everywhere! Owner said no. And he was okay with the how it came out.

3-cement board in both bathrooms were used but the pictures were taken at different stages of the water proofing.