Re: Bunch of uninformed comments here
I agree with your comments. I would also add that IBM did try and use their own RDBMS (DB2) as a backend to Notes rather than the native NSF format in the past. I heard that the reason this tanked was largley due to the honoring of Readers and Authors fields on Notes documents. IBM did get this working for DB2 but the performance wasn't any where near as good as the NSF db store.