Rendering any "Musical dissociative disorder" seems a bit stretched, because deviations relating tempo or synchronicity is intentional on part of the pianist, and it is not involuntary, nor pathologic. It's a matter of taste. Synchronicity is mathematical and absolute in written manuscript, but any tempo deviations via rubato really should involve BOTH hands, and not just one hand.
This, I disagree with, mostly because I think the pulse is often broken by this type of rubato. I think people use it often because it is by and far the easiest way to execute rubato in Chopin's music, and Chopin's music sounds awful without it (even the most mechanical of the etudes). But I also think that Chopin's music suffers from a loss of pulse, if not so much as from a lack of rubato.
Not really. Pulse is a subjective term. Pulse doesn't have to be broken in the presence of rubato, as music is a dynamic process that can embrace change within the same piece. Even a driving pulse needs a break from time to time to add a degree of contrast, hence different themes, etc. In proper use of rubato, it's the tempo
that is interrupted, not the rhythm
. In other words the music may slow down, but the elements which define rhythm remain intact - accents, meter, etc. Our sense of pulse is primarily driven by rhythm, so our perception of pulse within a piece doesn't suffer.
A lot of people forget that Chopin was an amateur. He never had a piano teacher. Even his most difficult pieces are 'easy' in the sense that he only wrote what came naturally to his hand.
Stated bluntly, but marginally true. He really didn't have the opportunity to delve deeply into the formal tools of composition. This can be seen with the use of awkward enharmonics within a given key signature. Even Józef Elsner allowed a free reign on composition during the "formal years" from 1826-29. Making up for any inadequacies, however, his understanding of form, style, musical creativity equaled or transcended his contemporaries.