Analysis for Office Reports using ABAP CDS Consumption Views - Questions on UI

Hello Experts,

We are building a bunch of Reports on SAP Analysis for Office by directly consuming CDS Views. We are not using BeX Designer specifically. Some of these reports are interlinked with each other using RRI (Transaction RSBBS).

Since all functionality is mostly driven by annotations defined in the CDS Consumption Views, here are a few questions that I struggled to find answer to.

1. How to keep a Column in the Report but set it as hidden by Default and User can add it from "Display Design Panel" - "Analysis" Tab based on requirement?

2. How to repeat the key in every cell of displayed data instead of cells being blank when they are sorted?

3. How to replace '#' with a blank space for characteristics that do not hold any value?

Thanks for your help in advance.

Best Regards,

Subhrangsu