Has anyone ever played (one of) the 4 Rhapsodies op.11, I just once tried the 3rd, good piece, but I think they're meant to be a whole piece, kind of a 4 movement sonata, they share themes, are they worthwile, ever done?

I think each one can stand alone. They are good pieces that sound more difficult than they are.

But is it an idea to play them as a whole? I'm not so sure, just got them in the fingers, but never tried them in public, I think Dohnanyi is a fine composer for the piano, he only never got this masterpiece out of his pen, the 4 rhapsodies just might come near to that, but it's quite a challenge to play them, would they make a point?

You are worrying about this too much.

Am I? I thought a quickening difference of opinions or difference in experience would help, your contribution is out of that league