Just what is his role? From what I have seen his role is at the snap of the ball is to stand straight up making him easier to block. Lineman just stand between Elam and the running back and he is blocked. If his duties is to not rush the QB then he is useless. If you don't have pressure up the middle the 3-4 defense won't stop any SEC offense.
A guy like Elam (a nose tackle) hopefully can do the following:
-immovable - the offense wants to push you around and open holes for the running game. Imagine a defensive lineman that you can't move....standing right in the middle where you want to run most of the time. It can really change an offense.
-change numbers - "if" he can be immovable enough to draw a double team block, then he shifts numbers in the box. For example let's say the offense has 7 blockers staring at 7 box defensemen. If Elam can draw a double team then the defense now has a man free. This is HUGE. In an ideal world he would command a double team every time....but he doesn't have to.....nor will he.
-disruptive - he can already be disruptive by just being immobile, however if he can force OL in a negative direction.....either backwards or an unwanted motion side/side.....this is huge. However, this takes talent and technique. Be sure to read about technique later.
-wall. Elam is 6'7".....with a nice wingspan. He's also really thick. Most QBs we face will be in the 6' to 6'3" range.....just having a guy that big in the middle could be a big plus.
-enable variable blitzes. Notice I didn't say who will do the blitzing. "If" he can plug the middle and/or draw double teams then there are now gaps and free defensive players to can either make plays or have lanes to blitz. In essence he frees up others to make plays. This means that he won't get huge numbers of tackles or sacks.
Now, onto technique. Technique for linemen is BEYOND HUGE. There are usually 2 main reasons why the vast, vast majority of good linemen are upperclassmen. The first reason is physical maturity. The 2nd is technique. In football, an upperclass veteran with sound technique will typically eat the lunch of a poor technical underclassmen......regardless of how "talented" they may be.
A guy like Elam probably didn't have to use technique much in HS. He probably just dominated based off size and talent alone. But now he has to play catch up in order to compete. This isn't an isolated problem. This is one that is actually the most common. Technique just usually isn't mastered in HS much of the time.
Now, what is Elam supposed to do? At the snap, he's supposed to punch out and hold the OC/OG at arm's length. As he holds him, he performs a "gap peek". Basically he peers around the OL to read where the play is going. Then, he has attempts to disengage and pursue the play.......or he continues to hold the point of attack to allow others to make the play. Now, those with good technique will perform this so quickly that they don't lose ground. Typically those with poor technique (usually underclassmen) will lose some ground in the process. Occasionally you will see NT's explode so violently off the line that they shove the middle of the line back into the QB's face. This usually happens with more elite NT's (with good technique) or when the talent disparity between OL and DL is large. For example, you'll see Bama NT's do it a lot but not super often with other teams.
And, on a side note, you can occasionally have guys explode out and overrun the play.....think Ware last yr. There were many times last yr where aware would explode upfield so fast and allow the RB or mobile QB to escape easily underneath. The OL just laughs when this happens. They know he can't make the play, so they'll let him blow past whenever he does it. This is a technique and discipline issue that usually improves with time. This is one of the reasons why we were torched by mobile QBs recently.
Now, onto Elam "standing straight up". This happens for several reasons. First is just plain poor conditioning....which is well documented. When people get tired they don't squat and get low as much. You see this in every sport....like the defensive stance in basketball. The 2nd is poor technique. Elam hasn't learned how to gain leverage. He hasn't learned how to play low. He hasn't used how to use his height/length as a strength. Which brings us to #3. Because he doesn't know how to use his height as an advantage, it's used against him. The OC/OGs that he is going up against are mostly 6'1" to 6'4". They are shorter/lower and likely has the leverage just based on height alone. Now understand that the vast majority of OL that he goes up against are going to be upperclassmen who are going to be stronger with better technique. He's just gonna be pushed up until he learns to compensate.
As far as Elam's play thus far. He's done ok. Not stellar, not poor. If not for injury he wouldn't have played a ton last yr. The staff knew he wasn't ready to start but unfortunately didn't have a choice. He "appears" to have the chops to be a good 2-down NT....but like any other position he must learn to play his position.