Hi,
Those shortcut are very close to how the source editor behave (text file with line number, ...). I believe this shortcut are not implemented for the visual editor. Not all shortcut working in a source editor will be.
If you want to see those shortcut implemented, you can check if someone already asked for them in the github repo for RStudio (https://github.com/rstudio/rstudio) and give a
or open a new feature request to ask for those.
Hope it helps