John, hats off for the undertake to practise and record that difficult mazurka!
In my opinion the tempo is ok so, I would not play it faster. Don't care for Rubinsteins or others vivace, find your own.You also play the pp places perceptible softer than the loud ones.
However according to your great postings like 10/1 I know that you really can do better on this piece. Chris already told in his matchless manner about rhythm issues, especially in the middle part, but also in the end part and in small doses almost everywhere. That is no rubato, there is uneveness. Please take it positive, because technical wise you are able to play that piece calm and relaxed. Listen to your right hand accompaignment beside the melody, lots of notes were missing.
Practising with metronome makes perhaps only sense if you switch it on for every quarter note, not every bar. After that some kind of rubato may start. Maybe you can manage to long for the more sophisticated expression things like the written accents in the score.
Keep on with that piece!
Yet, there is so much to be learnt by listening to the masters. My teacher insists one should not go and play any piece without listening to at least 3 different master interpretations, comparing them, and making up your mind what you want yours to sound like. I see the point of it, and yet I am not sure I agree with it.
Your teacher is right, I think. There is so much one can learn by listening to true masters of the art, regardless on piano or on organ. The only danger in my case is, that I often (if not always) try to speed up to soon in order to reach the speed I have from certain recordings in the ear. That is really a big problem for me, maybe for others too. But no doubt, everyone here can benefit through listening what the best of the best have to tell in their sidereal recording hours!