Shower Waterproofing

I installed hardie hyrdroboard in my shower, there is a window on the back wall of the shower, which I put hardie board all around it. Should I use silicone between the window frame and the hardie board? if I get it on the hyrdroboard will it prevent the liquid membrane from adhering?

I also heard folks say put a bead of silicone at the bottom of the hardie board where it meets concrete, then after it cures but the 6 inch mesh at the junction of floor to wall...is that correct?

On a separate note, I purchased the internal pipe cutter you use, practiced on spare pipe and installed the flofx drain...wonderful....now I see folks using a wheeler rex internal pipe cutter..

mixed reviews...but seems easier...curious if you've used...