About Ecclesiastes and Job, there are some parallels, but there are also some definite contrasts.
Job lost everything <> Solomon never lost a thing
Job was carefully righteousness <> Solomon fell away and by his own account lived for himself through much of his life.
Job complained to God about life but reaffirmed his faith in its meaning <> Solomon complained about life and said it was meaningless. I might add that Job spoke to God while Solomon spoke about God.
Job's wonderful declaration of faith ("I know that my Redeemer lives....") has no counterpart in Ecclesiastes. Here Job is speaking as a prophet pointing straight into the new covenant. There is no prophecy in Ecclesiaiastes.
Job in his pain is continually trying to break through to God <> Solomon does not seek anything from God, even at the conclusion.
Overall Job comes across as a much more hopeful book, especially in the ending where God reveals Himself to Job. Ecclesiastes winds up in a position of stoic faith without any sense of God's nearness. Not unlike certain strains of Mennonitism (present company excepted!
The underlying difference I think is that God is bringing Solomon back to where he began spiritually after a long period of unfaithfulness, but there is no net growth in his life. On the other hand, with Job God is taking a man who has been faithful throughout his life and is bringing him through to a higher level.
In terms of the Parable of the Talents, Solomon is the man who buried his talent and at the end hastily dug it up and put it in the bank - just in time! While Job is the man who invested his talent and earned ten-fold - certainly materially as the epilogue makes clear but more importantly his gain was spiritual.