Oftentimes on each side of the  equation there is a claim of 'cherry picking' or an accusation of 'cafeteria Catholics', yet this stuff continues unchallenged and  unabated.  In the case of the Immaculate Conception an omniscient God would know from all eternity Mary's response, there would be no surprise.  We might also do the same with the communion of saints and intercession.  Would a God that is omniscient require an intercession to what It already knows.  The claim is also that God is immutable.  When we pray, make our requests, pray for the dead are we not forgetting the attributes we humans have already placed on a Godhead;  Omniscience, Omnibenevolence, Omnipotence, Immutable, Absolute.