TT: English, the not-so-universal language

I just got another wonderful e-mail from the Bulgarian translator of Pops: A Life of Louis Armstrong . Here it is, verbatim and in its entirety:

I am writing to you again because I am wondering how to interpret Armstrong's explanation of [Sid] Catlett's irresponsibility: "He played the chicks, he ran with the cats, he played the horses, played the numbers" (especially the horses). I am not sure how to understand these metaphors, as well as how exactly they fit together.

Could you also explain to me the meaning of the title of Armstrong's article "Stomping Piano Man"?

Also, I am not sure if I understand correctly the title "Keep the horn percolating" and the related statement, made by Armstrong. Could you say that in other words in order to get closer to the meaning?

And one more question related to a chapter title. Which one of the meanings of "sigh" has to be used in the context of "I don't sigh for nothing"?

Believe me, I did my best...