As you can clearly see, for whatever benefit Greg Hardy can bring to making the 2015 Cowboys Pass Rush a force, the long term outlook is currently very ugly. There is nothing about the current state of the roster that would suggest it wouldn't be a good idea to draft defensive linemen with a 1st AND a 2nd round pick, let alone one of the two. I think the defensive end spot will end up being the focus, and I think in an ideal world Dallas finds a 1st rounder they like, and at the same time gets great production from Hardy and are able to lock him up long term midseason.
At DT, I think the team views the 1 Tech as a plug-and-play kind of spot, and the 3 Tech as one of the priority spots on the defense. The team wants their 1 Tech nosetackle on the field for 30 snaps a game at a maximum, so it is somewhere that Dallas is unlikely to add a first round pick to. Crawford could be worth signing to a deal similar to the original Ratliff and Hatcher extensions where you buy out a year of a rookie contract to pay less down the road. While he isn't Gerald McCoy, Crawford is a player who is well regarded by coaches, still developing, and was named a starter to PFF's All NFC East team. None of those scream 30 million guaranteed, but they also suggest he will be tough to replace without some real draft capital.
LB is another place where there is talk of adding a 1st rounder. Lee obviously needs to finally have a healthy season but just saying that doesn't really mean anything. There are plenty of examples of players labeled as injury prone who have been able to shed it (Matt Stafford, Rob Gronkwoski) but he still needs to do so. He's still under 6M in cap charge for 2015 and 2016, so even if he misses a game or two I think they'll find a spot for him long term. But you could see the MLB or SLB spots looked at in this draft early on.
Another spot where a first rounder could be spent is at cornerback. I'm of the belief that you build a defense from the front to the back, but I could see Dallas finally making an effort to find the right corners to fit the right scheme they want to play in this draft. At safety I think the team feels that is another area where you can plug guys in like Church and Wilcox, and if you keep everything in front of them they'll be fine. I actually agree with the philosophy, but I understand how others don't. Still, this is an awful draft for safeties so I don't think the position will be meaningfully addressed in 2015.
In the past 4 years the team has spent 1 first rounder on defense, 2 second rounders, and 2 third rounders. It has been exacerbated by the one 1st rounder (Claiborne) being a disaster, but there is a serious lack of young talent on the defense and I'd address as much of my draft capital on this side of the ball as I can. The offense is Romo-friendly in terms of enabling him to carve teams up, but what will really help the team get over that Divisional Round Hump is a defense that can slow opposing quarterbacks.