Knime sharing (next)

Following up the previous post “KNIME sharing” that will allow users to share a central installation I would like to check if these 2 questions are also possible:

1 -What about configuring a central installation that still allows us to use individual extensions? I want users to share the central installation but each user be able to install their own extensions and I don’t want to see other users extensions…
2 - I also want that users don’t get asked about their default workspace, so they won’t mess up with other directories, let’s say every user will have their default workspace on C:\Users\username\workspace

Thanks a lot for your help!.