Jags are improving more than you give credit for. With the amount of rookies and undrafted players they had on that team, it is a miricle that they even got 4 wins. Gus Bradley is an excellent coach, they have 11 draft picks, and still plenty of cap space.
Going 8-8 is unlikely, but they are in a weak division, with a very favourable strength of schedule. Stranger things have happened.
Luke Joekel should be fit, and the O-Line should be improved; I didn't really rate Zane Beadles in Denver but he is an upgrade for the Jags, no question. Again, they shouldn't be gunning for a QB in the first (or even the second if they can help it) when people like AJ McCarron should be available in the second or the third. And yes, Chad Henne deserves a chance to show the Jags what he can do with some weapons and something that resembles an offensive line - he did a good job considering the situation he was in. With the #3 overall pick, they should get Mack to go with Posluzny (a very underrated linebacker, if I do say so - he's an absolute tackling machine) and their linebacker corps is looking decent. They have addressed most of their key needs. They have upgraded their D-line as well with Clemons and Ziggy Hood, but they are not done yet. Then use the rest of the draft to fill out the secondary and wide recieving corps.(For the record, Cecil Shorts III is more of a bright spot in that Jags offense than Blackmon.). I do love the pick up of Gerhart, though MJD is probably going too. They're s still some very good players available in free agency. Hey, at least the weather's good in Jacksonville, right?