Stephen is correct about reefer meaning marijuana. In the US, marijuana is legal in some states as a medical treatment. Glaucoma is one of the conditions it is used for. However, at the time this sitcom was popular, cannibus was illegal and had to be used discreetly. Sherry (an alcoholic drink) is a legal, more socially-acceptable way to relieve stress -- as it relates to the hated manager.
When someone 'buys' a story, they believe it. To 'whip [something] out' means to remove something quickly from your purse or pocket, etc.
At 13:34 Dorothy touches her earring in order to pause for the audience to laugh at the line she just said. It could be said that her gesture is nonchalant and adds to the comedic effect.