Questions: Who first out of the pool?
Answer: Technically, Frank, but after him was Brad, as you can see in this photo, Brad gets out first.

Questions: Where is this mysterious button on Frank's corset you mention?
Answer: Look closely...

Questions: Where does Riff get the rag from ?
Answer: The rag is Riff's Hump as you can see in these photos. Riff pulls it from his upper left jacket, the same location as his hump. After he does this his hump is gone (see last pic)

Questions: Is there an air conditioner in the church window?
Answer: No! it is a window propped open. Look closely.