While it's not Pakistan, it is awfully close to Pakistan, and Kashgar may be the most conservative Muslim city in China. This means a few things for visitors looking to have a good time. 

Women should respect local custom to the extent of keeping arms and legs covered; no need to go to the extent of the veils you'll see all over town, but do use common sense to avoid hostile glares. 

Alcohol isn't given at any sit-down Uighur restaurant, and bringing your own bottle into many hole-in-the-wall places could result in rebuke. Beers are to be had, however. Hotel bars and Western-oriented eateries are a good bet. You might try the Seman and Chini Bagh Hotels as well as John's Cafe and the Caravan Cafe. Outdoor drinking isn't taboo, it's more a matter of who and where (Chinese and foreign visitors yes, conservative Uighur Muslims not so much)—several areas of town offer relaxing outdoor seating with beer and snacks. The area around Renmin Park offers a few such places.