1) Workspaces, userfiles, preferences, styles, etc are shared between 32-bit and 64-bit systems running on the same system. Therefore, if any settings are modified or active in one, they will also be modified or active in the other.
Additionally, if one version (eg 32-bit or 64-bit) is uninstalled and the user chooses to remove user files, all user files, workspaces, etc will be removed for the remaining installed version.
2) If the 32-bit and 64-bit version are both installed but in different languages, warning errors such as "stored uder language not available" will appear on launch.
This message can be dismissed and program will launch correctly. This is the result of shared user files.
3) The Repair Install window will appear when launching the 64-bit version after uninstalling the 32-bit build (or vice versa). You must provide access to source installer files (eg DVD, network) if they have not been installed. The program will launch correctly after repair.