Now, if a person can only have faith and works after after having been saved by grace how is a Protestant wrong when they say "saved by grace alone"?
>>It, for example, might prevent him from properly venerating the Catholic saints and learning ways to salvation from them.<<
Ways to salvation? You just stated that salvation is by grace alone! What more is there to know? You just admitted it's by God's grace alone and that will then produce faith and works.
No, he is saved when he is dead and judged. Not when he has faith from grace. He also has water and air form grace. That does not make him saved.
it is appointed unto men once to die, and after this the judgment (Hebrews 9:27)
faith and a good conscience, which some rejecting have made shipwreck concerning the faith (1 Timothy 1:19)
faith without works is dead (James 2:26)