I've did the trade back mocks many times, but you never know who or what deals are available.
With that many picks I would double dip on a few positions like DT (Walker/Black), LB, Edge, CB, OL, S, WR and a couple other positions.
We have so many hole to fill that trading back works really well for us this year!
Based their QB issues, I think the Steelers & Rams will be eager to trade with us.
We can take BPA on any of your listed positions over & over until the end of the draft...