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I can only help with the Flat view:
In Admin Menu->System->Preferences->Default Comment Display Mode, set it to Flat to make that the default for all new users that join your system.
Yes, it says 'comment display mode' but it affects how newBB works too.
Individual users can control this setting in their Profile. I don't believe you can alter this setting for existing users, they would have to do that themselves (unless you wanted to go into your DB and modify the setting manually for everyone).
Hope this helps, good luck,
--Julian
