I was hoping Steve would chime in here but he was sadly not available.
The bottom line is that you need one entry of each auth type. There IS a definitive list of the core auths but SP plugins can add extra ones so the final list will depend upon which plugins you have active.
What might be sensible here is if you tell me what plugins you have active and I can then create a SQL script to re-create your auths table as it should be. I assume you are comfortable with running a SQL script against your database.
Following that you would then need to perform the ‘rest’ of all auths, rebuild those relationships in your forums and clear out the auth caches but that comes afterwards.