I had the same issue of the missing DLC songs on my PS3. I fixed it by re-downloading my old RS1 save off of the PS+ server and the songs thru my system's "Account Management/Transaction Management/Download list".
By the way, there is a Tmp folder in the Rocksmith 2014 installation directory. It appears you can safely delete (or move, as I did) these file out of that directory and it will prevent the unpurchased DLC from showing up in the in-game track listings. Of course they might re-appear at some point (or new ones may appear that might need deleting/moving).
On mine songs without arrangements (like for lead) still show up but with an 'X' on the right. When you click it, it says there isn't a track for that song (I'm on the PC).
Steam Community Profile ID: dungeon-master
My Rocksmith 2014 Wiki - 1/29 - Have the Settings Editor form up. Todo: Create the Settings save script.
Steam Won't Let Rocksmith 2014 owners Download DLC
This is a Steam problem! I got the run around from their support all week they would only respond to me once a day telling me things I already knew like "You should be able to down load it try the website instead of the application." I respond yeah I tried that, then I'd have to wait till the next day. so I went out and researched the whole thing. Rocksmith says they have Hundreds of DLC tracks for 2014. It says it in their FAQ. How come I can only download 8 WTH. I figured they must mean the Rocksmith original DLC as well. So I laid out a big case to steam with links to back it up. They said
"I apologize for the inconvenience you went through.
It turns out that ownership of the original edition of Rocksmith is required in order to be able to purchase the "old" DLCs." I thought I was heated before, whoever was on the other side must be lying just to get rid of me is what I thought. So I called UbiSoft support (I googled the number) I told them everything. they said the old Rocksmith DLC "IS" available to Rocksmith 2014 owners but "THERE IS A PROBLEM WITH STEAM" we are working to resolve the issue.
I emailed steam support right away trying to be very respectful... I told them what I just heard. They said "The issue is being investigated but I cannot provide a release date or even a guarantee that a solution can be implemented." Why didn't you just say that before! I bought this product under the impression that, although i didn't like many of the songs, I could download the ones I like. Its the first thing I tried to do. The only thing holding me back is Steam. I refuse to pay them money that I don't have to! I WANT MY SONGS!