He never partied with them. Have you ever been to a party where you did not drink and get drunk. But, you were able to still enjoy yourself with your friends and family? There is no indication he partied with anyone but his own family. He went to the house of ill-repute to teach. He ate with them. But, I assure you, he did not get drunk with them. In fact, they chased him out because he called them to repentance.
What do you mean atone for my own sins? I cannot. I cannot atone for my own sins and you can't atone for your own sins either. Jesus Christ paid the price that if we repent, be baptized, receive the holy ghost and keep his commandments repenting all the days of our lives, we will reach eternal life. No man has the power nor the authority to atone for our own sins. Just ignorance to believe this.
While I largely agree with you, I would point you to Jesus' own words from Matthew 11:
16 But whereunto shall I liken this generation? It is like unto children sitting in the markets, and calling unto their fellows,
17 And saying, We have piped unto you, and ye have not danced; we have mourned unto you, and ye have not lamented.
18
For John came neither eating nor drinking, and they say, He hath a devil.
19
The Son of man came eating and drinking, and they say, Behold a man gluttonous, and a winebibber, a friend of publicans and sinners. But wisdom is justified of her children.
Let's not be too hasty to say that Jesus never drank alcohol. I guarantee He never drank to get drunk, but as we can see from His own words, He drank enough, at least during feasts, that others felt free to accuse Him of being a drunkard. John, as a Nazarite, didn't touch alcohol at all. Jesus was not a Nazarite.