youOme;
Do you have solid proof of his alcoholism? Did he go through a rehab? Does he have any domestic violence caused by drinking? A DUI or anything on public record of his alcoholism? If not it is your word against his and even if you have character witnesses from friends, a Judge won't even consider it. If I were you and you don't have concrete proof for your claim of alcoholism I would be careful about bringing it up. Character assasination is frowned on in custody cases. It used to work, but not anymore and the courts are leaning heavily toward Father rights. Use caution if you don't have the goods on him because Judge's have been known to award custody to the one that is being accused without proof.

Good luck,