I think it's good to get advice from many so you can make a positive choice. Everyone has something to offer, the main one is take care of your needs.

Son taking wine, well that is not good but often happens. Unless someone sees him this could open a big can of worms, him against you etc.

I think at this point I would step back too, keep some distance and stay busy doing what you enjoy.

A book on setting boundaries with blended families may be a good place to start, that is if you are considering moving forward with your relationship. I'm all for counselling to as with children other peoples don't come with a manual either :-)
Kate