Simply answering the question I would say the only position we do not need to draft is a strong safety. We have a starter in Ward and a young back up in Duke who are both likely to be on the roster through the 2015 season. Any draft pick in this position would be sat for three years behind Ward or would mean us giving up on a guy who has proven upside in Duke for another similar back up. There is just no significant roster improvement to be made here.
Every other position has a player out of contract next year so will need to be replaced, can utilise more than one player in that position effectively or has a player in that position who could be upgraded.
So why take this approach when others are identifying needs?
Because I think it highlights more succinctly that this roster could be upgraded in almost every position. As a result the Broncos should draft BPA until a position is not needed. I prefer this caveat to BPA than BPA at a position of need because that gets us into prioritising needs which is the worst form of drafting as you a more likely to reach for a player that you perceive as a greater need.
NB I have not included Kicker, Punter or Long Snapper in my thought process. They shouldn't be drafted.