Most of the items in this "checklist" were not apparent to me until after I had done some work on myself.
I could give a time when I exhibited a codie behaviour and another when I did the exact opposite.
For example, "I have problems identifying what I am feeling". Literally this statement never applied to me. But when I really dug underneath the layers of denial, I realized that I would examine what others were feeling and how they reacted before I decided what I was feeling. So, I "knew" what I was feeling - it was what the person I was with was feeling. But hardly ever did I give weight to what MY feelings were, thus they were left unexamined, invalidated - like a shopper who sees yesterday's expiration date on a milk carton and goes back in for another.
I would suggest reading "Codependent No More" by melody beattie. I swear they wrote it about me.