A Mazurka should be at a moderate tempo--the dance has some big moves in it, so it has a very full and billowy kind of feel, which you are compromise if the you play it too fast--120 or even a bit less--also, the Mazurka has a feel that is not a waltz feel, the accented beat is the third beat, not the first, as in a waltz--

In order to get the real feel, you should hear it played by someone who plays for dancers--if you are ever in the Philadelphia area, there is no one better that accordianist John Matulis, who is a master at most folkdances, and particularly Polish, Ukrainian, Russian--I believe he goes to NEFFA on occasion--

As to the Shaker stuff--I am not aware of any Shaker instrumental traditions, but I am very familiar with their dancing, having performed with Westwind, whose "Shaker Service" is the only performance of this religious ritual ever authorized by the Shakers--

The Shakers did not really dance, the music was used for a charismatic type ritual in which begins with the song sung slowly and which gradually becomes faster as various participants are possessed by the holy spirit--

There are a number of shaker hymnals, the lyrics to te hymns being original to the shakers, but the melodies were typically derived from English hymns and dances--a typical feature of a shaker melody is that it features an A and B part, which can generally be sung simultanieous for counterpoint, or offset for the effect of a round--