as long as you don't mind have the same auth.settings.hmac_key in the new application nothing will break, as far as i know, copying the data from auth_* tables to your new (fresh, without a single insert done) app.
@villas, VP .... csv import/export is totally usable for me .... villas method also works @all : beware of ids on every table if they are linked each other (references broken otherwise)
