There is a lot wrong with the Devils. Here are a few of my thoughts.
1) The coaching, the scheme they play does not suit that team at all. Ruff's system is unique and they are the only team playing this scheme. They are not strong enough along the boards which leads to a lot of lost pucks and easy high danger attempt's between the circles. They need a little size on the wing.
2) They are young, they make bad decisions every night when trying to clear the zone. Good coaching will correct this with time. For example, Adam Larson, struggled until Scott Stevens joined the staff. The next year Larson started looking like a top defensive prospect with time spent under Stevens.
3) Goaltending - Awful is being nice, Blackwood has too many gaffs per game, bad angles, and dropping to butterfly too early. The two AHL guys need time but both seem promising. Drafting a high-round goalie now still would not help the team in the next 2 to 4 years as he develops. Need someone in the system now to step up.
4) Severson, needs to be traded. People love him for his offensive ability but his defensive issues are greater than his plus on the offense side. Yes, every defenseman makes mistakes, but Severson's mistakes always lead to great scoring chances and most likely a goal. The 2-1 shorthanded goal against the Leafs is Severson at his best being bad. Not only does he misplay the puck on the point. but back on defense he looks confused on who to take, then moves over late to take away the pass. Only to stop and let leafs player behind him for an easy tap-in for a go-ahead goal.
5) Ty Smith, needs to go to the AHL and gain some confidence back. He constantly gets lost when the puck is in his feet and gets pushed off the puck behind the net and along the boards. He seems to be gripping the stick way too tight and misses easy passes, especially on the power-play point.
6) Pavel Zacha experiment has to end, he needs a fresh start somewhere. I liked him even when he wasn't scoring, now it seems his defense is hurting with his inability to produce offense, heck I would be happy if he would miss way fewer shots and get some on the net.
7) The obvious! they need 2-3 players to step up and show they can score goals. Hughes\Bratt can't be our main hope every night. Less missed shot on the net from the whole team would be a good start.
A ton of other crap can be listed, but long reads suck so I will stop with one last issue(Drafting, we need more mid-round draft picks to become contributors for this team. Oilers are a great example of what happens if you don't draft well after the first round)