Congrats, on the job.
If you worry about the crying, you can do things slowly.
How about putting him in the crib and sitting next to him (when dd has a bad day I hold her hand too), then slowly move towards the door?
For the milk in the middle of the night, you can try cutting ml. It worked for us. Every few nights I cut buck an oz and when we got to 2oz she didnt needed it any more.
Honestly, I did things very slowly because I couldnt take her crying. She had smiilar issues like your lo so I did everything very slowly.