He couldn't die though if the show is to survive.....his mortality was covered in the season finale...I really wasnt disappointed how they skipped that whole story line.

About the withdrawal symptons:

Remember he was in a chemically induced coma so the physical withdrawal symptons would have subsided. He is dealing with the mental withdrawal and didn't make it through the first show without falling back on them.

They mentioned he was rehabbing for 6 or 8 weeks I don't remember which.

They always question his judgement, they just normally relent. That is one of the interesting parts of the story for me. Wilson and Cuddy are trying to "train" him to be a more responsible doctor.

 

i think they gave themselves the option of going in whatever direction they want, when he was saying his leg was hurting and asking for the script for the vike.