Based on my experience, many alcoholics started out the way you describe. A little problem with alcohol practiced well eventually became alcoholism. Initially I could take it or leave it too and it gave me what I needed to come out of my shell and be fun and sociable. But with every drink and every month and year drinking I just became less fun and more disagreeable with worsening consequences.

If he drinks alcohol and becomes (physically?) combative or verbally abusive when otherwise he is not, is that not a negative? Since his behavior changes in a negative way then choosing to drink will carry consequences that will likely escalate over the years.

Your friend will ultimately be the one to decide. I had many friends "talk" to me about "my drinking" meaning that they considerately told me I drank too much and became obnoxious. I ignored them for a long time. Finally I had to look myself in the eye and make a decision. There was/is no reduced drinking for me, I can't drink alcohol, period. I hope your friend will be ok.