You disassemble your verses to permit your argument. While Jesus himself is sinless, I can agree with that. However you used Proverbs 31:4 yet I ask you to go further reading verses 5-7 as well.
4It is not for kings, O Lemuel, it is not for kings to drink wine; nor for princes strong drink:
5Lest they drink, and forget the law, and pervert the judgment of any of the afflicted.
6Give strong drink unto him that is ready to perish, and wine unto those that be of heavy hearts.
7Let him drink, and forget his poverty, and remember his misery no more.
It can be argued that on some occasions he would give intoxicating wine. Because it says so in the scriptures. It is easy to see why they offered it to him while he was on the cross, because it was in the Bible. Bible also says not to be a drunk alcoholic either so it would vary from case to case. As it does seem specific as to the circumstances. Being that they might have all been poor people, it would make sense that he gave them wine so that they would forget their poverty for the time being. They might have all been ready to die. It does say wine. And it doesn't exactly make him look bad for doing so. It still lines up either way you spin it.