ᐅ Basement Renovation: Waterproofing and Insulating / Loose Old Plaster

Hello,
We are currently renovating a 60-year-old house and have partially exposed the basement. It will be newly waterproofed, and the height of the external ground level will change.
Previously, there was a step and a concrete platform in front of the main entrance. Both were removed, as the entrance will be designed to be level with the ground.

I have the following questions:
- The old base plaster was/ is loose in some areas. I have already removed most of the loose material. How should the damaged spots be treated? Should a bitumen coating simply be applied over them, or do they need to be plastered first?
- Because of the higher ground level, the bitumen coating would actually need to be applied over the old topcoat plaster. Visually, this would not matter, since an external thermal insulation composite system (ETICS) will be installed later. Is it acceptable to do it this way?
- There are edges where the old basement wall meets the base plaster and where the base plaster meets the white topcoat plaster. How should these edges be handled when the basement/base insulation runs over them?

Thanks in advance for your advice

We took a closer look and decided to completely remove the old base coat plaster. After re-plastering, the surface is now clean and even.