For those saying Baun could play SAM in a 4-3, I just don't get it. He's at his best when he's rushing the passer. You are now asking him to fill the B gap and cover TE's or RB's. As far as his pass-rushing ability, the issue is going to be he'll facing NFL tackles each week who have 80 lbs and 4 inches on him. He's a good player but I would not take him at 17, especially for a 4-3 defense. You'd also be using your most valuable asset on a player who is likely sharing reps with Randy Gregory and Aldon Smith.
Now 2nd round? Sure, the risk is now worth the investment. You gamble on his talent and task the coaches to find a way to utilize his skillset.
I'm the Captain of the Edge argument, basically a 4-3 RDE and a 3-4 ROLB are the same player, but that argument loses credibility when the player is both shorter than the average Edge and weighs less than the average Edge. This isn't the TJ Watt debate again; Watt is 6'4" and 252 lbs. Dwight Freeney was only 6'1" but was 260 plus. Elvis Dumervil was that rare sub-6 footer, but he also weighed 250 plus and was drafted in the 4th round.