Number 1 is right, but you could put it a little differently in English: "Many of those present are drunk and reveling." μεθύοντες is a circumstantial participle describing the reveling, but we don't usually subordinate those things in English. (If we do, it implies that one of them is background information or a parenthetic afterthought, which isn't what the Greek means.)
In number 2, you're mistaking σοὶ for the dative of the personal pronoun; it's actually the possessive adjective σός, σή, σόν, "your." Any time you see a form like σοι inside a noun phrase, between the article and the noun (e.g. οἱ and φίλοι), you can be virtually certain that it's not the dative of the personal pronoun (even apart from matters of accent: the pronoun is enclitic).
EDIT: PS: Don't hesitate to translate with a present continuous tense ("is X-ing") when the Greek sentence is talking about action that is in progress at the time of speaking. The Greek present tense is used both for that and to describe things that generally or habitually occur. Your sentence 1 looks like action in progress; sentence 3 could be either in progress or habitual.
Dic mihi, Damoeta, 'cuium pecus' anne Latinum?